Electrodepositable coating composition

ABSTRACT

The present invention is directed to a phosphated epoxy resin comprising at least one terminal group comprising a phosphorous atom covalently bonded to the resin by a carbon-phosphorous bond or by a phosphoester linkage; and at least one carbamate functional group. The present invention is also directed towards aqueous resinous dispersions comprising the phosphated epoxy resin, methods of coating a substrate, coated substrates, and methods of making a phosphated epoxy resin.

FIELD OF THE INVENTION

The present invention is directed towards a phosphated epoxy resin,aqueous dispersions of said phosphated epoxy resin, electrodepositablecoating compositions containing said phosphated epoxy resin, coatedsubstrates, methods of coating substrates, and methods of making aphosphated epoxy resin.

BACKGROUND INFORMATION

Electrodeposition as a coating application method involves thedeposition of a film-forming composition onto a conductive substrateunder the influence of an applied electrical potential.Electrodeposition has gained popularity in the coatings industry becauseit provides higher paint utilization, outstanding corrosion resistance,and low environmental contamination as compared with non-electrophoreticcoating methods. Some coatings formed from electrodepositable coatingcompositions have lacked stability to hydrolysis resulting indegradation of the coating film from exposure to water. Other coatingsformed from electrodepositable coating compositions are stable tohydrolysis but require high heating temperatures in order to cure theelectrodeposited coating. Therefore, an electrodepositable coatingcomposition that cures at low temperatures and results in a coatinghaving hydrolytic stability is desired.

SUMMARY OF THE INVENTION

Disclosed herein is a phosphated epoxy resin comprising at least oneterminal group comprising a phosphorous atom covalently bonded to theresin by a carbon-phosphorous bond or by a phosphoester linkage; and atleast one carbamate functional group.

Also disclosed herein is an aqueous resinous dispersion comprising: (a)a phosphated epoxy resin comprising: (i) at least one terminal groupcomprising a phosphorous atom covalently bonded to the resin by acarbon-phosphorous bond or by a phosphoester linkage; and (ii) at leastone carbamate functional group; and (b) a curing agent.

Further disclosed herein is a method of making a phosphated epoxy resin,the method comprising: reacting an epoxy resin comprising at least oneterminal epoxide functional group and at least one pendant hydroxylfunctional group with a molecule comprising an isocyanato functionalgroup and a carbamate functional group, wherein the pendant hydroxylfunctional group and isocyanato functional group react to form aurethane linkage, whereby the molecule is incorporated into the epoxyresin to form a carbamate-functional epoxy resin; and further reactingthe carbamate-functional epoxy resin with a phosphoric acid, aphosphonic acid, a phosphinic acid, or combinations thereof, wherein theat least one terminal epoxide functional group of thecarbamate-functional epoxy resin reacts with an acid group of thephosphoric acid or phosphonic acid, whereby the phosphoric acid and/orthe phosphonic acid is incorporated into the carbamate-functional epoxyresin to form the phosphated epoxy resin comprising at least onecarbamate functional group.

Still further disclosed herein is a method of coating a substratecomprising electrophoretically depositing an aqueous resinous dispersiononto the substrate to form a coating on the substrate, the aqueousresinous dispersion comprising: (a) a phosphated epoxy resin comprising:(i) at least one terminal group comprising a phosphorous atom covalentlybonded to the resin by a carbon-phosphorous bond or by a phosphoesterlinkage; and (ii) at least one carbamate functional group; and (b) acuring agent.

Also disclosed herein is a coated substrate, wherein the coatedsubstrate is at least partially coated with an aqueous resinousdispersion comprising: (a) a phosphated epoxy resin comprising: (i) atleast one terminal group comprising a phosphorous atom covalently bondedto the resin by a carbon-phosphorous bond or by a phosphoester linkage;and (ii) at least one carbamate functional group; and (b) a curingagent.

Further disclosed herein is a part at least partially coated with anaqueous resinous dispersion comprising: (a) a phosphated epoxy resincomprising: (i) at least one terminal group comprising a phosphorousatom covalently bonded to the resin by a carbon-phosphorous bond or by aphosphoester linkage; and (ii) at least one carbamate functional group;and (b) a curing agent.

Still further disclosed herein is a vehicle comprising a part at leastpartially coated with an aqueous resinous dispersion comprising: (a) aphosphated epoxy resin comprising: (i) at least one terminal groupcomprising a phosphorous atom covalently bonded to the resin by acarbon-phosphorous bond or by a phosphoester linkage; and (ii) at leastone carbamate functional group; and (b) a curing agent.

Also disclosed herein is a vehicle at least partially coated with anaqueous resinous dispersion comprising: (a) a phosphated epoxy resincomprising: (i) at least one terminal group comprising a phosphorousatom covalently bonded to the resin by a carbon-phosphorous bond or by aphosphoester linkage; and (ii) at least one carbamate functional group;and (b) a curing agent.

Further disclosed herein is an aqueous resinous dispersion comprising:(a) a phosphated epoxy resin; and (b) a carbamate-functional oligomercomprising at least two carbamate functional groups.

DETAILED DESCRIPTION OF THE INVENTION

As stated above, the present invention is directed to a phosphated epoxyresin comprising: at least one terminal group comprising a phosphorousatom covalently bonded to the resin by a carbon-phosphorous bond or by aphosphoester linkage; and at least one carbamate functional group.

As used herein, term “phosphated epoxy resin” refers to an ungelledepoxy resin derived from at least an epoxy-functional monomer, oligomer,or polymer, and a phosphorous-atom containing compound, such as aphosphorous acid. By “ungelled” is meant the resins are substantiallyfree of crosslinking and have an intrinsic viscosity when dissolved in asuitable solvent, as determined, for example, in accordance withASTM-D1795 or ASTM-D4243. The intrinsic viscosity of the reactionproduct is an indication of its molecular weight. A gelled reactionproduct, on the other hand, since it is of essentially infinitely highmolecular weight due to substantial crosslinking of the resin molecules,will have an intrinsic viscosity too high to measure (i.e., cannot bedissolved in a solvent). As used herein, a reaction product that is“substantially free of crosslinking” refers to a reaction product thathas a z-average molecular weight (Mz) of less than 500,000 g/mol. Itwill be understood that although referred to as a phosphated epoxyresin, the phosphated epoxy resin may be described as being derived fromepoxy resins in which at least a portion or all of the epoxidefunctionality has been reacted and is no longer present.

According to the present invention, the phosphated epoxy resin comprisesat least one terminal group comprising a phosphorous atom covalentlybonded to the resin by a carbon-phosphorous bond or by a phosphoesterlinkage. The phosphorous atom may have one, two, three or fourcovalently bonded oxygen atom(s). At least one of the oxygen atoms maybe covalently bonded to the phosphorous atom by a double bond. As usedherein, the term “phosphoester linkage” refers to a covalent bondbetween a carbon atom and an oxygen of a phosphoester group, asdemonstrated in the following exemplary structure:

wherein R₁ and R₂ each represent hydrogen, hydroxyl, an alkyl radical,an aryl radical, or an additional phosphoester group. As used herein,the term “phosphoester group” refers to an oxygen atom covalently bondedto an alkyl radical or an aryl radical, wherein the oxygen atom is alsocovalently bonded to a phosphorous atom that is bonded to an additionaloxygen atom by a double bond. For example, in the structure above, R₁ orR₂ will be considered to be a phosphoester group when R₁ or R₂ is O—R,wherein R is an alkyl radical or an aryl radical. It will be understoodthat the phosphorous atom may comprise three phosphoester groups,including the phosphoester linkage.

The terminal group may comprise phosphate, organophosphate, phosphonate,organophosphonate, phosphinate, organophosphinate, or, if multipleterminal groups are present, combinations thereof.

The terminal group comprising a phosphorous atom covalently bonded tothe resin by a phosphoester linkage may be according to the structure:

wherein R₁ and R₂ each independently represent hydrogen, hydroxyl, analkyl radical, an aryl radical, or a phosphoester group. Multipleterminal groups according to this structure may be present on thephosphated epoxy resin. For example, the phosphated epoxy resin maycomprise at least two terminal groups comprising a phosphorous atomcovalently bonded to the resin by a phosphoester linkage. A phosphatedepoxy resin having two terminal groups comprising a phosphorous atomcovalently bonded to the resin by a phosphoester linkage may beaccording to the structure:

wherein R₁, R₂, R₃ and R₄ each independently represent hydrogen,hydroxyl, an alkyl radical, an aryl radical, or a phosphoester group,and R represents the remainder of the phosphated epoxy resin. Theremainder of the phosphated epoxy resin may comprise the remainder orresidue of an epoxy-functional polymer. As used herein, the term“remainder or residue of an epoxy-functional polymer” with respect to anR-group refers to the polymeric backbone of the epoxy-functional polymerand any substituents present thereon that are not shown in the molecularstructure. The remainder of the phosphated epoxy resin and/or remainderor residue of the epoxy-functional polymer may be aliphatic, aromatic,cyclic, acyclic, alicylic or heterocyclic. It should be understood thatwhen R₁, R₂, R₃ or R₄ are hydroxyl, the R_(x)-group comprises aphosphoacid group that may further react with an epoxide functionalgroups of an additional epoxy-containing polymer that results in aphosphated epoxy resin having an increased chain length with thephosphorous atom present in the polymer backbone. In addition, branchingfrom the phosphorous acid may occur if two phosphoacid groups arepresent and each reacts with an epoxide functional group of anepoxy-containing polymer.

The phosphated epoxy resin may further comprise other terminalfunctional groups including, for example, epoxide, hydroxyl, thiol,amino, urea, amide, and/or carboxylic acid functional groups.Alternatively, the phosphated epoxy resin may be substantially free,essentially free, or completely free of any or all of these functionalgroups. As used herein, the term “substantially free”, “essentiallyfree” or “completely free” with respect to the presence of a functionalgroup means that the functional group is present in an amount of 3% orless, 0.1% or less, or 0.00%, respectively, the percentage based uponthe total number of the functional group relative to the total number ofepoxide, hydroxyl, thiol, amino, urea, amide, and/or carboxylic acidfunctional groups.

As used herein, the term “terminal” with respect to a functional groupof a polymer refers to a functional group that is not pendant to thepolymeric backbone of the polymer and forms a terminus of the polymericchain. As used herein, the term “pendant” with respect to a functionalgroup refers to a functional group of a polymer that is present as aside group to the polymeric backbone and does not form a terminus of thepolymeric chain. The term “pendant” may also refer to a substituted orunsubstituted hydrocarbon moiety attached to the larger polymericbackbone. The term “pendant group” may be used to refer to both apendant functional group or a functional group present in a pendantchain. As used herein, the term “pendant chain” refers to a substitutedor unsubstituted hydrocarbon moiety extending from the main polymerbackbone. An exemplary structure showing a linear polymer backbonehaving terminal and pendant groups, and an exemplary structure showing abranched polymer backbone having terminal and pendant groups areproduced below. The terminal groups are represented by the letter ‘A’and the pendant groups are represented by the letter ‘B’, with thepolymer backbone represented by a wavy line.

A further non-limiting example of a polymer having terminal groups andpendant groups is the epoxy-functional polymer resulting from thereaction of an excess of diglycidyl ether of bisphenol A with bisphenolA. The resulting polymer has at least one terminal epoxide group(assuming at least one end of the polymeric chain terminates withdiglycidyl ether of bisphenol A) and at least one pendant hydroxyl groupresulting from the epoxide ring-opening reaction of a hydroxylfunctional group from bisphenol A with an epoxide functional group fromdiglycidyl ether of bisphenol A. In addition, a pendant chain may beintroduced by reacting a compound with a pendant functional group on thebackbone, such as, for example, the pendant hydroxyl functional group.

According to the present invention, the phosphated epoxy resin of thepresent invention may comprise a reaction product of a reaction mixturecomprising an epoxy-functional polymer and a phosphorous acid.Accordingly, the phosphated epoxy resin may comprise the residue of anepoxy-functional polymer and a phosphorous acid.

The epoxy-functional polymer may comprise a polyepoxide. The polyepoxidemay comprise a polyglycidyl ether of a polyphenol, such as bisphenol A.As will be appreciated, such polyepoxides can be produced byetherification of a polyphenol with an epichlorohydrin in the presenceof an alkali. Suitable polyphenols include, without limitation,1,1-bis(4-hydroxyphenyl)ethane; 2,2-bis(4-hydroxyphenyl)propane;1,1-bis(4-hydroxyphenyl)isobutane;2,2-bis(4-hydroxytertiarybutylphenyl)propane;bis(2-hydroxynaphthyl)methane; 1,5-dihydroxynaphthalene;1,1-bis(4-hydroxy-3-allylphenyl)ethane; and4,4-bis(4′-hydroxyphenyl)valeric acid. Another class of polyepoxides maybe produced similarly from polyphenol resins.

The epoxy-functional polymer may comprise a polymeric backbonecomprising a polyepoxide that has been chain extended by reaction with acompound having at least two functional groups reactive with epoxygroups, such as, for example, di-functional compounds such as diols,diphenols (including Bisphenol A), dicarboxylic acids, dithiols, and/ordiamines. These reactions may chain-extend the polymeric backbone of theepoxy resin and increase its molecular weight. The epoxide functionalgroups from the polyepoxide should be present in a stoichiometric excesssuch that the resulting polymer comprises at least one terminal epoxidefunctional group.

In addition to the polyepoxide(s), the reaction mixture may comprise amonomeric monoepoxide such as monoglycidyl ethers of alcohols andphenols, such as phenyl glycidyl ether, and glycidyl esters ofmonocarboxylic acids such as glycidyl neodecanoate. Alternatively, thereaction mixture may be substantially free, essentially free, orcompletely free of such monomers, and the phosphated epoxy resin mayalso be substantially free, essentially free, or completely free of theresidue of such monomers. The terms substantially free, essentiallyfree, and completely free as used with respect to the monomericmonoepoxide means less than 5% by weight, less than 1% by weight, and0.0% by weight, respectively, of monoepoxide are present, if at all,based on the total weight of the reaction mixture or based on the weightof the phosphated epoxy resin.

The epoxy-functional polymer may be substantially free, essentiallyfree, or completely free of pendant epoxide functional groups. As usedherein, an epoxy-functional polymer is substantially free of pendantepoxide functional groups when 1 or less pendant epoxide functionalgroup are present per molecule of the epoxy-functional polymer. As usedherein, an epoxy-functional polymer is essentially free of pendantepoxide functional groups when 0.1 or less pendant epoxide functionalgroup are present per molecule of the epoxy-functional polymer. As usedherein, an epoxy-functional polymer is completely free of pendantepoxide functional groups when pendant epoxide functional group are notpresent in the epoxy-functional polymer.

The terminal group comprising a phosphorous atom covalently bonded tothe resin by a phosphoester linkage may be produced by the reaction of aphosphorous acid with a terminal epoxide group of an epoxy-functionalpolymer. The phosphorous acid may comprise a phosphoric acid, aphosphonic acid, a phosphinic acid, or combinations thereof.

Non-limiting examples of phosphoric acids that could react with epoxidefunctional groups include a 100 percent orthophosphoric acid or aphosphoric acid aqueous solution such as is referred to as an 85 percentphosphoric acid. Other forms of phosphoric acid such as superphosphoricacid, diphosphoric acid and triphosphoric acid may be used. Also, thepolymeric or partial anhydrides of phosphoric acids can be employed. Theaqueous phosphoric acids that may comprise about 70 to 90 percent, suchas about 85 percent phosphoric acid are employed.

Non-limiting examples of phosphonic acids are organophosphonic acids ofthe structure:

wherein R is organic radical such as those having a total of 1-30, suchas 6-18 carbons. R can be aliphatic, aromatic or mixedaliphatic/aromatic and can be an unsubstituted hydrocarbon or asubstituted hydrocarbon.

Non-limiting examples of phosphinic acids are organophosphinic acids ofthe structure:

wherein R and R′ are each independently hydrogen or an organic radical.Examples of such radicals are those having a total of 1-30, such as 6-18carbons. The organic component of the phosphinic acid (R, R′) can bealiphatic, aromatic or mixed aliphatic/aromatic. R and R′ can be anunsubstituted hydrocarbon or a substituted hydrocarbon.

Non-limiting specific examples of organophosphonic acids andorganophosphinic acids are: 3-amino propyl phosphonic acid,4-methoxyphenyl phosphonic acid, benzylphosphonic acid, butylphosphonicacid, carboxyethylphosphonic acid, diphenylphosphinic acid,dodecylphosphonic acid, ethylidenediphosphonic acid,heptadecylphosphonic acid, methylbenzylphosphinic acid,naphthylmethylphosphinic acid, octadecylphosphonic acid, octylphosphonicacid, pentylphosphonic acid, methylphenylphosphinic acid,phenylphosphonic acid, styrene phosphonic acid, dodecylbis-1,12-phosphonic acid, poly(ethylene glycol) phosphonic acid,including mixtures thereof.

The phosphated epoxy resin may be substantially free, essentially free,or completely free of pendant groups comprising a phosphorous atomcovalently bonded to the resin by a carbon-phosphorous bond or by aphosphoester linkage. As used herein, a phosphated epoxy resin issubstantially free of such pendant groups when less than 1 theoreticalpendant phosphorous atom-containing groups are present per molecule ofthe resin. As used herein, the theoretical pendant phosphorousatom-containing group refers to a group that would theoretically bepresent as a pendant phosphorous atom-containing group in view of theraw materials and method used to make the phosphated epoxy resin. Forexample, an epoxy-containing polymer having one pendant epoxidefunctional group that reacts with a phosphorous acid would have onetheoretical pendant phosphorous-containing groups because thephosphorous acid would be expected to react with the pendant epoxidefunctional group. Another example is a phosphorous-containing moleculethat is reacted or grafted with a pendant group present on a polymersuch as, for example, the reaction of a pendant unsaturated group on thepolymer with a phosphorous-containing compound. Such reaction would beexpected to result in a pendant phosphorous atom-containing group. Asused herein, a phosphated epoxy resin is essentially free of suchpendant groups when less than 0.1 theoretical pendant phosphorousatom-containing groups are present per molecule of the resin. As usedherein, a phosphated epoxy resin is completely free of such pendantgroups when such pendant groups are not theoretically present in thephosphated epoxy resin.

The phosphated epoxy resin may comprise functional groups such as, forexample, carbamate, thiol, amino, urea, amide, and carboxylic acidfunctional groups. Alternatively, the phosphated epoxy resin may besubstantially free, essentially free, or completely free of any of thesefunctional groups. As used herein, the term “substantially free”,“essentially free” or “completely free” with respect to the presence ofa functional group means that the functional group is present in anamount of 3% or less, 0.1% or less, or 0.00%, respectively, thepercentage based upon the total number of the functional group relativeto the total number of carbamate, thiol, amino, urea, amide, andcarboxylic acid functional groups.

According to the present invention, the phosphated epoxy resin maycomprise at least one carbamate functional group. As used herein, theterm “carbamate functional group” refers to a functional group on thephosphated epoxy resin having the structure:

wherein R₁ comprises the remainder of the phosphated epoxy resin and mayoptionally further comprise an additional organic linking group bindingthe carbamate functional group to the polymeric backbone of thephosphated epoxy resin, and R₂ comprises hydrogen, an alkyl radical, oran aryl radical. The carbamate may be a pendant group, a terminal group,or, if multiple carbamate groups are present, combinations thereof. Anorganic linking group may bind the epoxy resin backbone and thecarbamate functional group together. A specific non-limiting example ofa moiety comprising the carbamate functional group and an organiclinking group binding the carbamate functional group to the epoxy resinbackbone may be the structure:

wherein R represents the remainder of the phosphated epoxy resin.

The phosphated epoxy resin may further comprise at least one hydroxylfunctional group in addition to the carbamate functional group(s). Thehydroxyl group may be present as a substituent on the epoxy-functionalpolymer itself, or the hydroxyl group may be the result of aring-opening reaction of an epoxide functional group of theepoxy-functional polymer.

In addition to carbamate functional group(s) and/or hydroxyl functionalgroup(s), the phosphated epoxy resin may optionally further compriseadditional functional groups, such as, for example, thiol, amino, urea,amide, and carboxylic acid functional groups. Alternatively, thephosphated epoxy resin may be substantially free, essentially free, orcompletely free of any or all of these functional groups. As usedherein, the term “substantially free”, “essentially free” or “completelyfree” with respect to the presence of a functional group means that thefunctional group is present in an amount of 3% or less, 0.1% or less, or0.00%, respectively, the percentage based upon the total number of thefunctional group relative to the total number of carbamate, hydroxyl,thiol, amino, urea, amide, and carboxylic acid functional groups.

The phosphated epoxy resin may comprise at least one constitutional unitA comprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical. For example, R₁ and R₂ each independentlymay represent hydrogen, methyl, ethyl, propyl, butyl, or phenyl groups.In addition, the aromatic rings may be substituted.

The phosphated epoxy resin may further comprise at least oneconstitutional unit B comprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical. For example, R₁ and R₂ each independentlymay represent hydrogen, methyl, ethyl, propyl, butyl, or phenyl groups.In addition, the aromatic rings may be substituted.

The phosphated epoxy resin may comprise a ratio of constitutional unit Ato constitutional unit B from 1:20 to 20:1, such as 1:10 to 10:1, suchas 1:5 to 5:1, such as 1:2 to 2:1, such as 1:1.1 to 1.1:1.

The phosphated epoxy resin may comprise the structure:

wherein m is 1 to 2,000 and n is 0 to 2,000; R₁ and R₂ eachindependently represent hydrogen, an alkyl radical or an aryl radical;R₃ and R₄ each independently represent hydrogen, hydroxyl, an alkylradical, an aryl radical, or a phosphoester group. For example, R₁ andR₂ each independently may represent hydrogen, methyl, ethyl, propyl,butyl, or phenyl groups. In addition, the aromatic rings may besubstituted. Although the structure shows a block polymer comprising acarbamate functional block and a hydroxyl functional block, the polymermay comprise random polymer segments and polymerization products aswell.

According to the present invention, the phosphated epoxy resin may bedispersed in a dispersing medium comprising water. The phosphated epoxyresin may be, prior to or during dispersion in a dispersing mediumcomprising water, at least partially neutralized by, for example,treating with a base to form a water-dispersible anionic saltgroup-containing phosphated epoxy resin. As used herein, the term“water-dispersible” means that a material is adapted to be solubilized,dispersed, and/or emulsified in water. As used herein, the term “anionicsalt group-containing phosphated epoxy resin” refers to a phosphatedepoxy resin comprising at least partially neutralized anionic functionalgroups, such as, for example, phosphoric acid groups, that impart anegative charge to the resin. Non-limiting examples of suitable basesinclude both organic and inorganic bases. Illustrative examples ofsuitable bases are ammonia, monoalkylamines, dialkylamines, ortrialkylamines such as ethylamine, propylamine, dimethylamine,dibutylamine and cyclohexylamine; monoalkanolamine, dialkanolamine ortrialkanolamine such as ethanolamine, diethanolamine, triethanolamine,propanolamine, isopropanolamine, diisopropanolamine,dimethylethanolamine and diethylethanolamine; morpholines, e.g.,N-methylmorpholine or N-ethylmorpholine. The percent of neutralizationis such as would make the resin water-dispersible and electrophoretic.One or more of such bases may be added to the phosphated epoxy resin inan amount sufficient to theoretically neutralize the phosphated epoxyresin from, for example, 20 to 200 percent, such as 40 to 150 percent,such as 60 to 120 percent of theoretical neutralization.

The z-average molecular weight (M_(z)) of the phosphated epoxy resin maybe at least 20,000 g/mol, such as at least 50,000 g/mol, such as atleast 75,000 g/mol, and may be no more than 500,000 g/mol, such as nomore than 350,000 g/mol, such as no more than 300,000 g/mol, such as nomore than 250,000 g/mol, such as no more than 150,000 g/mol. Themolecular weight of the phosphated epoxy resin may be 20,000 g/mol to500,000 g/mol, 20,000 g/mol to 350,000 g/mol, such as 50,000 g/mol to300,000 g/mol, such as 75,000 g/mol to 250,000 g/mol, such as 75,000g/mol to 150,000 g/mol. As used herein, the term “z-average molecularweight” or “(M_(z))” means the z-average molecular weight (M_(z)) asdetermined by gel permeation chromatography (GPC) using Waters 2695separation module with a Waters 410 differential refractometer (RIdetector), linear polystyrene standards having molecular weights of from580 Da to 365,000 Da, dimethylformamide (DMF) with 0.05M lithium bromide(LiBr) as the eluent at a flow rate of 0.5 mL/min, and one ShodexAsahipak GF-510 HQ column (300×7.5 mm, 5 μm) for separation.

The present invention is also directed towards a method of making aphosphated epoxy resin comprising at least one carbamate functionalgroup. The method may comprise reacting an epoxy-functional polymercomprising at least one terminal epoxide functional group and at leastone pendant hydroxyl functional group with a molecule comprising anisocyanato functional group and a carbamate functional group, whereinthe pendant hydroxyl functional group and isocyanato functional groupreact to form a urethane linkage, whereby the molecule is incorporatedinto the epoxy resin to form a carbamate-functional epoxy resin. Themolar ratio of the molecule to hydroxyl functional groups of theepoxy-functional polymer may be 1:20 to 20:1, such as 1:10 to 10:1, suchas 1:5 to 5:1, such as 1:2 to 2:1, such as 1:1.1 to 1.1:1, such that theresulting carbamate-functional epoxy resin has a carbamate functionalgroup to hydroxyl functional group ratio of 1:20 to 20:1, such as 1:10to 10:1, such as 1:5 to 5:1, such as 1:2 to 2:1, such as 1:1.1 to 1.1:1.When reacting the epoxy-functional polymer with the molecule comprisingan isocyanato functional group and a carbamate functional group, theepoxy-functional polymer may be substantially free, essentially free, orcompletely free of pendant or terminal groups comprising a phosphorousatom. The carbamate-functional epoxy resin may be further reacted withphosphoric acid, phosphonic acid, phosphinic acid, or combinationsthereof, wherein the at least one terminal epoxide functional group ofthe carbamate-functional epoxy resin reacts with an acid group of thephosphoric acid, phosphonic acid, or phosphinic acid whereby thephosphoric acid, the phosphonic acid, and/or phosphinic acid isincorporated into the carbamate-functional epoxy resin through aphosphoester bond to form a phosphated, carbamate-functional epoxyresin. The phosphated, carbamate-functional epoxy resin may optionallybe neutralized with a base.

The present invention is also directed towards an aqueous resinousdispersion comprising the phosphated epoxy resin described above and acuring agent. The aqueous resinous dispersion comprises a dispersion ofthe phosphated epoxy resin in a continuous phase of an aqueous medium.For example, the aqueous medium may comprise at least 80% by weightwater, based on the total weight of the aqueous medium. The aqueousmedium may further comprise one or more organic solvents. Examples ofsuitable organic solvents include oxygenated organic solvents, such asmonoalkyl ethers of ethylene glycol, diethylene glycol, propyleneglycol, and dipropylene glycol which contain from 1 to 10 carbon atomsin the alkyl group, such as the monoethyl and monobutyl ethers of theseglycols. Examples of other at least partially water-miscible solventsinclude alcohols such as ethanol, isopropanol, butanol and diacetonealcohol. If used, the amount of organic solvent present in the aqueousdispersion may be less than 20% by weight, such as less than 10% byweight, such as less than 5% by weight, such as less than 2% by weight,with the % by weight being based on the total weight of the aqueousmedium. The curing agent, and any other optional ingredients, may bepresent is the dispersed resinous phase, the continuous phase, a thirdphase that is neither the resinous phase nor the continuous phase, or ina combination of the resinous phase, continuous phase and/or thirdphase, and may be either solubilized, dispersed, or a combinationthereof.

According to the present invention, the phosphated epoxy resin may bepresent in the aqueous resinous dispersion in an amount of at least 50%by weight, such as at least 55% by weight, such as at least 60% byweight, and may be present in an amount of no more than 90% by weight,such as no more than 80% by weight, such as no more than 75% by weight,based on the total weight of the resin solids of the aqueous resinousdispersion. The phosphated epoxy resin may be present in the aqueousresinous dispersion in an amount 50% to 90%, such as 55% to 80%, such as60% to 75%, based on the total weight of the resin solids of the aqueousresinous dispersion.

The present invention is also directed to an aqueous resinous dispersioncomprising a phosphated epoxy resin and a carbamate-functional oligomercomprising at least two carbamate groups. When the phosphated epoxyresin comprises at least one carbamate functional group, thecarbamate-functional oligomer may optionally be present in the aqueousresinous dispersion. The carbamate-functional oligomer may comprisethree or more carbamate functional groups and may comprise thestructure:

The carbamate-functional oligomer may be present in the aqueous resinousdispersion in an amount of at least 10% by weight, such as at least 15%by weight, such as at least 20% by weight, and may be present in anamount of no more than 50% by weight, such as no more than 45% byweight, such as no more than 40% by weight, based on the total weight ofthe resin solids of the aqueous resinous dispersion. Thecarbamate-functional oligomer may be present in the aqueous resinousdispersion in an amount of 10% to 55% by weight, such as 15% to 50% byweight, such as 20% to 45% by weight, based on the total weight of theresin solids of the aqueous resinous dispersion.

According to the present invention, when the aqueous resinous dispersioncomprises the carbamate-functional oligomer described above, it has beensurprisingly discovered that the coating deposited from the resinousdispersion may demonstrate a decreased length of filiform corrosion whencompared to a comparative coating composition that does not include thecarbamate-functional oligomer, as measured according to the FiliformCorrosion Test Method. The improvement in filiform corrosion resistance(i.e., decreased length of filament) is observed regardless of whetherthe phosphated epoxy resin comprises a carbamate functional group.Accordingly, the present invention is also directed to an aqueousresinous dispersion comprising a phosphated epoxy resin and thecarbamate-functional oligomer.

As used herein, the “Filiform Corrosion Test Method” refers toinscribing a 3.75 inch by 3.75 inch (95.25 mm by 95.25 mm) “X” into thecoated panel surface to a sufficient depth to penetrate any surfacecoating to expose the underlying metal and placing the panelshorizontally in a desiccator containing a thin layer of 12 Nhydrochloric acid (HCl) for 1 hour at ambient temperature, wherein onlythe HCl fumes shall come into contact with the sample. Within 5 minutesof removal from the desiccator, the panels are placed in a verticalorientation in a humidity cabinet maintained at 40° C. and 80% relativehumidity for 960 hours. The panels are then visually inspected for thepresence of filaments, i.e., corrosion damage extending from the scribedarea into the area underneath the coating, and any filaments present aremeasured for length from the scribe. Duplicate panels are included fortesting and the results are averaged. The length of the filaments may bereferred to as the length of filiform corrosion.

According to the present invention, the aqueous resinous dispersions ofthe present invention may further comprise a curing agent. The curingagent may comprise at least two functional groups that react with thereactive groups, such as carbamate and active hydrogen functionalgroups, of the phosphated epoxy resin to cure the coating composition toform a coating. As used herein, the term “cure”, “cured” or similarterms, as used in connection with the aqueous resinous dispersiondescribed herein, means that at least a portion of the components thatform the aqueous resinous dispersion are crosslinked to form a thermosetcoating. Additionally, curing of the aqueous resinous dispersion refersto subjecting said composition to curing conditions (e.g., elevatedtemperature) leading to the reaction of the reactive functional groupsof the components of the aqueous resinous dispersion, and resulting inthe crosslinking of the components of the composition and formation ofan at least partially cured coating. Non-limiting examples of suitablecuring agents are at least partially blocked polyisocyanates, aminoplastresins and phenoplast resins, such as phenolformaldehyde condensatesincluding allyl ether derivatives thereof.

Suitable at least partially blocked polyisocyanates include aliphaticpolyisocyanates, aromatic polyisocyanates, and mixtures thereof. Thecuring agent may comprise an at least partially blocked aliphaticpolyisocyanate. Suitable at least partially blocked aliphaticpolyisocyanates include, for example, fully blocked aliphaticpolyisocyanates, such as those described in U.S. Pat. No. 3,984,299 atcol. 1 line 57 to col. 3 line 15, this portion of which is incorporatedherein by reference, or partially blocked aliphatic polyisocyanates thatare reacted with the polymer backbone, such as is described in U.S. Pat.No. 3,947,338 at col. 2 line 65 to col. 4 line 30, this portion of whichis also incorporated herein by reference. By “blocked” is meant that theisocyanate groups have been reacted with a compound such that theresultant blocked isocyanate group is stable at ambient temperature butreactive at elevated temperatures, such as between 90° C. and 200° C.The polyisocyanate curing agent may be a fully blocked polyisocyanatewith substantially no free isocyanato groups.

The polyisocyanate curing agent may comprise a diisocyanate, higherfunctional polyisocyanates or combinations thereof. For example, thepolyisocyanate curing agent may comprise aliphatic and/or aromaticpolyisocyanates. Aliphatic polyisocyanates may include (i) alkyleneisocyanates, such as trimethylene diisocyanate, tetramethylenediisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate(“HDI”), 1,2-propylene diisocyanate, 1,2-butylene diisocyanate,2,3-butylene diisocyanate, 1,3-butylene diisocyanate, ethylidenediisocyanate, and butylidene diisocyanate, and (ii) cycloalkyleneisocyanates, such as 1,3-cyclopentane diisocyanate, 1,4-cyclohexanediisocyanate, 1,2-cyclohexane diisocyanate, isophorone diisocyanate,methylene bis(4-cyclohexylisocyanate) (“HMDI”), the cyclo-trimer of1,6-hexmethylene diisocyanate (also known as the isocyanurate trimer ofHDI, commercially available as Desmodur N3300 from Convestro AG), andmeta-tetramethylxylylene diisocyanate (commercially available as TMXDI®from Allnex SA). Aromatic polyisocyanates may include (i) aryleneisocyanates, such as m-phenylene diisocyanate, p-phenylene diisocyanate,1,5-naphthalene diisocyanate and 1,4-naphthalene diisocyanate, and (ii)alkarylene isocyanates, such as 4,4′-diphenylene methane (“MDI”),2,4-tolylene or 2,6-tolylene diisocyanate (“TDI”), or mixtures thereof,4,4-toluidine diisocyanate and xylylene diisocyanate. Triisocyanates,such as triphenyl methane-4,4′,4″-triisocyanate, 1,3,5-triisocyanatobenzene and 2,4,6-triisocyanato toluene, tetraisocyanates, such as4,4′-diphenyldimethyl methane-2,2′,5,5′-tetraisocyanate, and polymerizedpolyisocyanates, such as tolylene diisocyanate dimers and trimers andthe like, may also be used. The curing agent may comprise a blockedpolyisocyanate selected from a polymeric polyisocyanate, such aspolymeric HDI, polymeric MDI, polymeric isophorone diisocyanate, and thelike. The curing agent may also comprise a blocked trimer ofhexamethylene diisocyanate available as Desmodur N3300® from CovestroAG. Mixtures of polyisocyanate curing agents may also be used.

The polyisocyanate curing agent may be at least partially blocked withat least one blocking agent selected from a 1,2-alkane diol, for example1,2-propanediol; a 1,3-alkane diol, for example 1,3-butanediol; abenzylic alcohol, for example, benzyl alcohol; an allylic alcohol, forexample, allyl alcohol; caprolactam; a dialkylamine, for exampledibutylamine; and mixtures thereof. The polyisocyanate curing agent maybe at least partially blocked with at least one 1,2-alkane diol havingthree or more carbon atoms, for example 1,2-butanediol.

Other suitable blocking agents include aliphatic, cycloaliphatic, oraromatic alkyl monoalcohols or phenolic compounds, including, forexample, lower aliphatic alcohols, such as methanol, ethanol, andn-butanol; cycloaliphatic alcohols, such as cyclohexanol; aromatic-alkylalcohols, such as phenyl carbinol and methylphenyl carbinol; andphenolic compounds, such as phenol itself and substituted phenolswherein the substituents do not affect coating operations, such ascresol and nitrophenol. Glycol ethers and glycol amines may also be usedas blocking agents. Suitable glycol ethers include ethylene glycol butylether, diethylene glycol butyl ether, ethylene glycol methyl ether andpropylene glycol methyl ether. Other suitable blocking agents includeoximes, such as methyl ethyl ketoxime, acetone oxime and cyclohexanoneoxime.

Alternatively, the aqueous resinous dispersion may be substantiallyfree, essentially free, or completely free of blocked polyisocyanatecuring agents. As used herein, the term “substantially free”,“essentially free” or “completely free” with respect to the presence ofblocked polyisocyanate curing agents means that the blockedpolyisocyanate curing agent is present, if at all, in an amount of 5% orless, 1% or less, or 0.00%, respectively, the percentage based upon thetotal weight of the resin solids of the aqueous resinous dispersion.

The curing agent may comprise an aminoplast resin. Aminoplast resins arecondensation products of an aldehyde with an amino- or amido-groupcarrying substance. Condensation products obtained from the reaction ofalcohols and an aldehyde with melamine, urea or benzoguanamine may beused. However, condensation products of other amines and amides may alsobe employed, for example, aldehyde condensates of triazines, diazines,triazoles, guanidines, guanamines and alkyl- and aryl-substitutedderivatives of such compounds, including alkyl- and aryl-substitutedureas and alkyl- and aryl-substituted melamines. Some examples of suchcompounds are N,N′-dimethyl urea, benzourea, dicyandiamide,formaguanamine, acetoguanamine, ammeline,2-chloro-4,6-diamino-1,3,5-triazine,6-methyl-2,4-diamino-1,3,5-triazine, 3,5-diaminotriazole,triaminopyrimidine, 2-mercapto-4,6-diaminopyrimidine,3,4,6-tris(ethylamino)-1,3,5-triazine, and the like. Suitable aldehydesinclude formaldehyde, acetaldehyde, crotonaldehyde, acrolein,benzaldehyde, furfural, glyoxal and the like.

The aminoplast resins may contain methylol or similar alkylol groups,and at least a portion of these alkylol groups may be etherified by areaction with an alcohol to provide organic solvent-soluble resins. Anymonohydric alcohol may be employed for this purpose, including suchalcohols as methanol, ethanol, propanol, butanol, pentanol, hexanol,heptanol and others, as well as benzyl alcohol and other aromaticalcohols, cyclic alcohol such as cyclohexanol, monoethers of glycolssuch as Cello solves and Carbitols, and halogen-substituted or othersubstituted alcohols, such as 3-chloropropanol and butoxyethanol.

Non-limiting examples of commercially available aminoplast resins arethose available under the trademark CYMEL® from Allnex Belgium SA/NV,such as CYMEL 1130 and 1156, and RESIMENE® from INEOS Melamines, such asRESIMENE 750 and 753. Examples of suitable aminoplast resins alsoinclude those described in U.S. Pat. No. 3,937,679 at col. 16, line 3 tocol. 17, line 47, this portion of which being hereby incorporated byreference. As is disclosed in the aforementioned portion of the '679patent, the aminoplast may be used in combination with the methylolphenol ethers.

Phenoplast resins are formed by the condensation of an aldehyde and aphenol. Suitable aldehydes include formaldehyde and acetaldehyde.Methylene-releasing and aldehyde-releasing agents, such asparaformaldehyde and hexamethylene tetramine, may also be utilized asthe aldehyde agent. Various phenols may be used, such as phenol itself,a cresol, or a substituted phenol in which a substituted orunsubstituted hydrocarbon radical having either a straight chain, abranched chain or a cyclic structure is substituted for a hydrogen inthe aromatic ring. Mixtures of phenols may also be employed. Somespecific examples of suitable phenols are p-phenylphenol,p-tert-butylphenol, p-tert-amylphenol, cyclopentylphenol and unsaturatedhydrocarbon-substituted phenols, such as the monobutenyl phenolscontaining a butenyl group in ortho, meta or para position, and wherethe double bond occurs in various positions in the unsaturatedhydrocarbon chain.

Aminoplast and phenoplast resins, as described above, are described inU.S. Pat. No. 4,812,215 at col. 6, line 20 to col. 7, line 12, the citedportion of which being incorporated herein by reference.

The curing agent may be present in the aqueous resinous dispersion in anamount of at least 10% by weight, such as at least 20% by weight, suchas at least 25% by weight, and may be present in an amount of no morethan 50% by weight, such as no more than 45% by weight, such as no morethan 40% by weight, based on the total weight of the resin solids of theaqueous resinous dispersion. The curing agent may be present in theaqueous resinous dispersion in an amount of 10% to 50% by weight, suchas 20% to 45% by weight, such as 25% to 40% by weight, based on thetotal weight of the resin solids of the aqueous resinous dispersion.

According to the present invention, the aqueous resinous dispersions mayoptionally comprise a catalyst to catalyze the reaction between thecuring agent and the phosphated epoxy resin. As used herein, the term“catalyst” does not include the phosphorous acid reacted with the epoxyresin or any remaining unbound and free phosphorous acid present in thecomposition. Non-limiting examples of catalysts include latent acidcatalysts, specific examples of which are identified in WO 2007/118024at [0031] and include, but are not limited to, ammoniumhexafluoroantimonate, quaternary salts of SbF₆ (e.g., NACURE® XC-7231),t-amine salts of SbF₆ (e.g., NACURE® XC-9223), Zn salts of triflic acid(e.g., NACURE® A202 and A218), quaternary salts of triflic acid (e.g.,NACURE® XC-A230), and diethylamine salts of triflic acid (e.g., NACURE®A233), all commercially available from King Industries, and/or mixturesthereof. Latent acid catalysts may be formed by preparing a derivativeof an acid catalyst such as para-toluenesulfonic acid (pTSA) or othersulfonic acids. For example, a well-known group of blocked acidcatalysts are amine salts of aromatic sulfonic acids, such as pyridiniumpara-toluenesulfonate. Such sulfonate salts are less active than thefree acid in promoting crosslinking. During cure, the catalysts may beactivated by heating.

Alternatively, the aqueous resinous dispersions may be substantiallyfree, essentially free, or completely free of catalyst. As used herein,the term substantially free, essentially free, and completely free withrespect to the amount of catalyst refers to compositions having lessthan 0.1% by weight, less than 0.01% by weight, and 0.00% by weight,respectively, of catalyst, based upon the total weight of the resinsolids.

According to the present invention, the aqueous resinous dispersions maycomprise other optional ingredients, such as a pigment composition and,if desired, various additives such as fillers, plasticizers,anti-oxidants, biocides, auxiliary polymers or oligomers such asacrylics, polyesters, additional epoxy or phosphated epoxy resins (otherthan the phosphated epoxy resin described above), rheology modifiers, UVlight absorbers and stabilizers, hindered amine light stabilizers,defoamers, fungicides, dispersing aids, flow control agents,surfactants, wetting agents, flatting agents to control gloss, orcombinations thereof. Alternatively, the aqueous resinous dispersion maybe completely free of any of the optional ingredients, i.e., theoptional ingredient is not present in the aqueous resinous dispersion.If present, the pigment composition may comprise organic or inorganicpigments, such as, for example, iron oxides, lead oxides, strontiumchromate, carbon black, coal dust, titanium dioxide, talc, bariumsulfate, as well as color pigments such as cadmium yellow, cadmium red,chromium yellow and the like. Further non-limiting examples of pigmentsinclude metal flakes or particles, such as those of aluminum or zinc, aswell as platy inorganic particles, such as talc or clay. It isunderstood that the size of any insoluble optional ingredients can benano or micron when added to the formulation and that the size and shapeof the particle may affect the activity and the rheological propertiesof the formulation. Both nano and micron sized particles are suitablefor this invention. The pigment content of the dispersion may beexpressed as the pigment-to-resin weight ratio and may be within therange of 0.03:1 to 4.00:1, when pigment is present. The other additivesmentioned above may be present in the aqueous resinous dispersion inamounts of 0.01% to 3% by weight, based on total weight of the resinsolids of the aqueous resinous dispersion.

According to the present invention, the aqueous resinous dispersions mayoptionally comprise a corrosion inhibitor. As used herein, the term“corrosion inhibitor” refers to any material that may reduce thecorrosion rate of a metal substrate such as ferrous substrate oraluminum alloy. The corrosion inhibitor may be soluble or insolublewithin the resinous dispersion and may display corrosion inhibitingproperties only when the pH of the metal surface is raised or lowered asa result of corrosion. It is understood that the size and shape ofinsoluble corrosion inhibiting particles may affect the rate at whichthe active species is released as well as rheological properties. Bothnano and micron sized particles are suitable for this invention.Suitable corrosion inhibitors include but are not limited to metaloxides of zinc, manganese, cerium, praseodymium, lanthanum, and yttrium,organosilicon based materials and their oxides, iron phosphate, zincphosphate, calcium ion-exchanged silica, colloidal silica, syntheticamorphous silica, vanadates and molybdates, such as calcium molybdate,zinc molybdate, barium molybdate, strontium molybdate, and mixturesthereof. Suitable calcium ion-exchanged silica is commercially availablefrom W. R. Grace & Co. as SHIELDEX. AC3 and/or SHIELDEX. C303. Suitableamorphous silica is available from W. R. Grace & Co. as SYLOID. Suitablezinc hydroxyl phosphate is commercially available from ElementisSpecialties, Inc. as NALZIN. 2. The aqueous resinous dispersion may alsocomprise one or more organic corrosion inhibitors. Examples of suchinhibitors include but are not limited to sulfur and/or nitrogencontaining heterocyclic compounds, examples of which include azoles,thiophene, hydrazine and derivatives, pyrrole, disulfides andderivatives thereof. Such organic corrosion inhibitors are described inU.S. Publication No. 2013/0065985, paragraph no. 52, which is herebyincorporated by reference. Specific non-limiting examples of corrosioninhibitors comprising sulfur and/or nitrogen containing heterocycliccompounds include 2-mercaptobenzothiazole, 2,5-dimercaptothiadiazole andtheir sodium, zinc, and potassium salts, the Cobratec® line of productsbased on benzotriazole and tolytriazole commercially available from PMCSpecialties Group, Inc., Hybricor®204, 204S, and Inhibicor 1000commercially available from WPC Technologies. The corrosion inhibitorsmay be present in the aqueous resinous dispersion in an amount of 0.1 to60% by weight, such as 5 to 40% by weight, such as 10 to 25% by weight,based on the total resin solids weight of the dispersion. The corrosioninhibitors may remain substantially unreacted after the aqueous resinousdispersion is applied and cured to form a coating. As used herein, theterm “substantially unreacted” with respect to the corrosion inhibitormeans that at least partially curing the deposited aqueous resinousdispersion, less than 75% of the total corrosion inhibitor by weight,based on the total weight of the corrosion inhibitor, has been bound toa resin, curing agent or pigment within the coating film via covalentbonds.

Alternatively, the aqueous resinous dispersions may be substantiallyfree, essentially free, or completely free of any of the optionalingredients discussed above. As used herein, the term substantiallyfree, essentially free, and completely free with respect to the amountof optional ingredient refers to compositions having less than 0.1% byweight, less than 0.01% by weight, and 0.00% by weight, respectively, ofthe optional ingredient, based upon the total weight of the resinsolids.

According to the present invention, the total solids content of theaqueous resinous dispersions may be at least 1% by weight, such as atleast 5% by weight, and may be no more than 50% by weight, such as nomore than 40% by weight, such as no more than 20% by weight, based onthe total weight of the aqueous resinous dispersion. The total solidscontent of the aqueous resinous dispersion may be from 1% to 50% byweight, such as 5% to 40% by weight, such as 5% to 20% by weight, basedon the total weight of the aqueous resinous dispersion. As used herein,“total solids” refers to the non-volatile content of the aqueousresinous dispersion, i.e., materials which will not volatilize whenheated to 110° C. for 60 minutes.

The present invention is also directed to electrodepositable coatingcompositions comprising the phosphated epoxy resins described above. Theelectrodepositable coating composition may comprise the aqueous resinousdispersions comprising the phosphated epoxy resins as the aqueousresinous dispersion itself may be an electrodepositable coatingcomposition. For example, the electrodepositable coating composition maycomprise an aqueous resinous dispersion comprising the phosphated epoxyresin comprising at least one carbamate functional group, the curingagent, and optionally the carbamate-functional oligomer. Theelectrodepositable coating composition may also comprise an aqueousresinous dispersion comprising the phosphated epoxy resin, the curingagent and the carbamate-functional oligomer.

As used herein, the term “electrodepositable coating composition” refersto a composition that is capable of being deposited onto an electricallyconductive substrate under the influence of an applied electricalpotential.

The present invention is also directed to a method of coating asubstrate, comprising electrophoretically depositing the aqueousresinous dispersions described above onto the substrate to form acoating on the substrate. According to the present invention such methodmay comprise electrophoretically applying an aqueous resinous dispersionas described above to at least a portion of the substrate and curing thecoating composition to form an at least partially cured coating on thesubstrate. According to the present invention, the method may comprise(a) electrophoretically depositing onto at least a portion of thesubstrate an aqueous resinous dispersion of the present invention and(b) heating the coated substrate to a temperature and for a timesufficient to cure the electrodeposited coating on the substrate.According to the present invention, the method may optionally furthercomprise (c) applying directly to the at least partially curedelectrodeposited coating one or more pigment-containing coatingcompositions and/or one or more pigment-free coating compositions toform an additional coating layer over at least a portion of the at leastpartially cured electrodeposited coating, and (d) curing the additionalcoating layer by allowing it to set at ambient temperature or byapplying a sufficient energy from an external energy source to thecoated substrate of step (c) to a condition and for a time sufficient toat least partially cure the additional coating layer. Non-limitingexamples of external energy sources include thermal energy and radiationsuch as ultraviolet, infrared or microwave.

According to the present invention, the aqueous resinous dispersions ofthe present invention may be deposited upon an electrically conductivesubstrate by placing the composition in contact with an electricallyconductive cathode and an electrically conductive anode, with thesurface to be coated being the anode. Following contact with the aqueousresinous dispersion, an adherent film of the coating composition isdeposited on the anode when a sufficient voltage is impressed betweenthe electrodes. The conditions under which the electrodeposition iscarried out are, in general, similar to those used in electrodepositionof other types of coatings. The applied voltage may be varied and canbe, for example, as low as one volt to as high as several thousandvolts, such as between 50 and 500 volts. The current density may bebetween 0.1 ampere and 15 amperes per square foot and tends to decreaseduring electrodeposition indicating the formation of an insulating film.

Once the aqueous resinous dispersion is electrodeposited over at least aportion of the electroconductive substrate, the coated substrate may beheated to a temperature and for a time sufficient to at least partiallycure the electrodeposited coating on the substrate. As used herein, theterm “at least partially cured” with respect to a coating refers to acoating formed by subjecting the coating composition to curingconditions such that a chemical reaction of at least a portion of thereactive groups of the components of the coating composition occurs toform a thermoset or crosslinked coating. The coated substrate may beheated to a temperature ranging from 160° F. to 450° F. (71.1° C. to232.2° C.), such as from 200° F. to 300° F. (93.3° C. to 148.9° C.),such as from 200° F. to 250° F. (93.3° C. to 121.1° C.). The curing timemay be dependent upon the curing temperature as well as other variables,for example, film thickness of the electrodeposited coating, level andtype of catalyst present in the composition and the like. For purposesof the present invention, all that is necessary is that the time besufficient to effect cure of the coating on the substrate, such asdetermined by the Double Acetone Rub Test Method described herein. Forexample, the curing time may range from 10 to 60 minutes, such as 20 to40 minutes. The thickness of the resultant cured electrodepositedcoating may range from 1 to 50 microns, such as 15 to 50 microns.

According to the present invention, the coating deposited from theresinous dispersion describe above may cure at a bake temperature of250° F. in 60 minutes or less, as measured by the Double Acetone RubTest Method.

As used herein, the “Double Acetone Rub Test Method” refers to rubbingthe baked panels with an acetone soaked WYPALL X80 disposable paper wipemanufactured by Kimberly-Clark. The number of double acetone rub(s) (onerub forward and rub backward constitutes a double rub) are counted untilthe coating is removed and the metal substrate is exposed, or until apredetermined number of rubs is reached without exposing the underlyingsubstrate surface. A coating may be considered to be cured if itsurvives at least 25 double acetone rubs without reaching the substrate;such as at least 50 double acetone rubs without reaching the substrate;such as at least 75 double acetone rubs without reaching the substrate;such as at least 100 double acetone rubs without reaching the substrate.

The aqueous resinous dispersion may be electrophoretically depositedupon any electrically conductive substrate. Suitable substrates includemetal substrates, metal alloy substrates, and/or substrates that havebeen metallized, such as nickel-plated plastic. Additionally, substratesmay comprise non-metal conductive materials including compositematerials such as, for example, materials comprising carbon fibers orconductive carbon. According to the present invention, the metal ormetal alloy may comprise, for example, cold rolled steel, hot rolledsteel, steel coated with zinc metal, zinc compounds, or zinc alloys,such as electrogalvanized steel, hot-dipped galvanized steel,galvanealed steel, nickel-plated steel, and steel plated with zincalloy. The substrate may comprise an aluminum alloy. Non-limitingexamples of aluminum alloys include the 1XXX, 2XXX, 3XXX, 4XXX, 5XXX,6XXX, or 7XXX series as well as clad aluminum alloys and cast aluminumalloys, such as, for example, the A356 series. The substrate maycomprise a magnesium alloy. Non-limiting examples of magnesium alloys ofthe AZ31B, AZ91C, AM60B, or EV31A series also may be used as thesubstrate. The substrate used in the present invention may also compriseother suitable non-ferrous metals such as titanium or copper, as well asalloys of these materials. Suitable metal substrates for use in thepresent invention include those that are often used in the assembly ofvehicular bodies (e.g., without limitation, door, body panel, trunk decklid, roof panel, hood, roof and/or stringers, rivets, landing gearcomponents, and/or skins used on an aircraft), a vehicular frame,vehicular parts, motorcycles, wheels, industrial structures andcomponents such as appliances, including washers, dryers, refrigerators,stoves, dishwashers, and the like, agricultural equipment, lawn andgarden equipment, air conditioning units, heat pump units, lawnfurniture, and other articles. The substrate may comprise a vehicle or aportion or part thereof. The term “vehicle” is used in its broadestsense and includes all types of aircraft, spacecraft, watercraft, andground vehicles. For example, a vehicle can include, aircraft such asairplanes including private aircraft, and small, medium, or largecommercial passenger, freight, and military aircraft; helicopters,including private, commercial, and military helicopters; aerospacevehicles including, rockets and other spacecraft. A vehicle can includea ground vehicle such as, for example, trailers, cars, trucks, buses,vans, construction vehicles, golf carts, motorcycles, bicycles, trains,and railroad cars. A vehicle can also include watercraft such as, forexample, ships, boats, and hovercraft. The aqueous resinous dispersionmay be utilized to coat surfaces and parts thereof. A part may includemultiple surfaces. A part may include a portion of a larger part,assembly, or apparatus. A portion of a part may be coated with theaqueous resinous dispersion of the present invention or the entire partmay be coated.

The metal substrate may be in the shape of a cylinder, such as a pipe,including, for example, a cast iron pipe. The metal substrate also maybe in the form of, for example, a sheet of metal or a fabricated part.The substrate may also comprise conductive or non-conductive substratesat least partially coated with a conductive coating. The conductivecoating may comprise a conductive agent such as, for example, graphene,conductive carbon black, conductive polymers, or conductive additives.It will also be understood that the substrate may be pretreated with apretreatment solution. Non-limiting examples of a pretreatment solutioninclude a zinc phosphate pretreatment solution such as, for example,those described in U.S. Pat. Nos. 4,793,867 and 5,588,989, a zirconiumcontaining pretreatment solution such as, for example, those describedin U.S. Pat. Nos. 7,749,368 and 8,673,091. Other non-limiting examplesof a pretreatment solution include those comprising trivalent chromium,hexavalent chromium, lithium salts, permanganate, rare earth metals,such as yttrium, or lanthanides, such as cerium. Another non-limitingexample of a suitable surface pretreatment solution is a solgel, such asthose comprising alkoxy-silanes, alkoxy-zirconates, and/oralkoxy-titanates. Alternatively, the substrate may be a non-pretreatedsubstrate, such as a bare substrate, that is not pretreated by apretreatment solution.

The substrate may optionally be subjected to other treatments prior tocoating. For example, the substrate may be cleaned, cleaned anddeoxidized, anodized, acid pickled, plasma treated, laser treated, orion vapor deposition (IVD) treated. These optional treatments may beused on their own or in combination with a pretreatment solution. Thesubstrate may be new (i.e., newly constructed or fabricated) or it maybe refurbished, such as, for example, in the case of refinishing orrepairing a component of an automobile or aircraft.

As mentioned above, the substrate coated by the aqueous resinousdispersion of the present invention may comprise a vehicle. For example,the aqueous resinous dispersion of the present invention may be utilizedin coating a F/A-18 jet or related aircraft such as the F/A-18E SuperHornet and F/A-18F (produced by McDonnell Douglas/Boeing and Northrop);in coating the Boeing 787 Dreamliner, 737, 747, 717 passenger jetaircraft, and related aircraft (produced by Boeing CommercialAirplanes); in coating the V-22 Osprey; VH-92, S-92, and relatedaircraft (produced by NAVAIR and Sikorsky); in coating the G650, G600,G550, G500, G450, and related aircraft (produced by Gulfstream); and incoating the A350, A320, A330, and related aircraft (produced by Airbus).The aqueous resinous dispersion may be used as a coating for use in anysuitable commercial, military, or general aviation aircraft such as, forexample, those produced by Bombardier Inc. and/or Bombardier Aerospacesuch as the Canadair Regional Jet (CRJ) and related aircraft; producedby Lockheed Martin such as the F-22 Raptor, the F-35 Lightning, andrelated aircraft; produced by Northrop Grumman such as the B-2 Spiritand related aircraft; produced by Pilatus Aircraft Ltd.; produced byEclipse Aviation Corporation; or produced by Eclipse Aerospace (KestrelAircraft).

The aqueous resinous dispersion may also be used to coat surfaces ofvehicles. Non-limiting examples thereof include fuel tank surfaces andother surfaces exposed to or potentially exposed to aerospace solvents,aerospace hydraulic fluids, and aerospace fuels.

The aqueous resinous dispersion of the present invention may be utilizedin an electrocoating layer that is part of a multi-layer coatingcomposite comprising a substrate with various coating layers. Thecoating layers may optionally include a pretreatment layer, such as aphosphate layer (e.g., zinc phosphate layer) or metal oxide layer (e.g.,zirconium oxide layer), an electrocoating layer which results from theaqueous resinous dispersion of the present invention, optionally one ormore primer layer(s) and suitable topcoat layer(s) (e.g., base coat,clear coat layer, pigmented monocoat, and color-plus-clear compositecompositions). It is understood that suitable additional coating layersinclude any of those known in the art, and each independently may bewaterborne, solventborne, in solid particulate form (i.e., a powdercoating composition), or in the form of a powder slurry. The additionalcoating compositions may comprise a film-forming polymer, crosslinkingmaterial and, if a colored base coat or monocoat, one or more pigments.The primer layer(s) may optionally be disposed between theelectrocoating layer and the topcoat layer(s). Alternatively, thetopcoat layer(s) may be omitted such that the composite comprises theelectrocoating layer and one or more primer layer(s).

Moreover, the topcoat layer(s) may be applied directly onto theelectrodepositable coating layer. In other words, the substrate may lacka primer layer such that the composite comprises the electrocoatinglayer and one or more topcoat layer(s). For example, a basecoat layermay be applied directly onto at least a portion of theelectrodepositable coating layer.

It will also be understood that any of the topcoat layers may be appliedonto an underlying layer despite the fact that the underlying layer hasnot been fully cured. For example, a clearcoat layer may be applied ontoa basecoat layer even though the basecoat layer has not been subjectedto a curing step (wet-on-wet). Both layers may then be cured during asubsequent curing step thereby eliminating the need to cure the basecoatlayer and the clearcoat layer separately.

According to the present invention, additional ingredients such ascolorants and fillers may be present in the various coating compositionsfrom which the top coat layers result. Any suitable colorants andfillers may be used. For example, the colorant may be added to thecoating in any suitable form, such as discrete particles, dispersions,solutions and/or flakes. A single colorant or a mixture of two or morecolorants can be used in the coatings of the present invention. Itshould be noted that, in general, the colorant can be present in a layerof the multi-layer composite in any amount sufficient to impart thedesired property, visual and/or color effect.

Example colorants include pigments, dyes and tints, such as those usedin the paint industry and/or listed in the Dry Color ManufacturersAssociation (DCMA), as well as special effect compositions. A colorantmay include, for example, a finely divided solid powder that isinsoluble but wettable under the conditions of use. A colorant may beorganic or inorganic and may be agglomerated or non-agglomerated.Colorants may be incorporated into the coatings by grinding or simplemixing. Colorants may be incorporated by grinding into the coating byuse of a grind vehicle, such as an acrylic grind vehicle, the use ofwhich will be familiar to one skilled in the art.

Example pigments and/or pigment compositions include, but are notlimited to, carbazole dioxazine crude pigment, azo, monoazo, disazo,naphthol AS, salt type (lakes), benzimidazolone, condensation, metalcomplex, isoindolinone, isoindoline and polycyclic phthalocyanine,quinacridone, perylene, perinone, diketopyrrolo pyrrole, thioindigo,anthraquinone, indanthrone, anthrapyrimidine, flavanthrone, pyranthrone,anthanthrone, dioxazine, triarylcarbonium, quinophthalone pigments,diketo pyrrolo pyrrole red (“DPP red BO”), titanium dioxide, carbonblack, zinc oxide, antimony oxide, etc. and organic or inorganic UVopacifying pigments such as iron oxide, transparent red or yellow ironoxide, phthalocyanine blue and mixtures thereof. The terms “pigment” and“colored filler” can be used interchangeably.

Example dyes include, but are not limited to, those that are solventand/or aqueous based such as acid dyes, azoic dyes, basic dyes, directdyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, mordantdyes, for example, bismuth vanadate, anthraquinone, perylene, aluminum,quinacridone, thiazole, thiazine, azo, indigoid, nitro, nitroso,oxazine, phthalocyanine, quinoline, stilbene, and triphenyl methane.

Example tints include, but are not limited to, pigments dispersed inwater-based or water miscible carriers such as AQUA-CHEM 896commercially available from Degussa, Inc., CHARISMA COLORANTS andMAXITONER INDUSTRIAL COLORANTS commercially available from AccurateDispersions division of Eastman Chemical, Inc.

The colorant may be in the form of a dispersion including, but notlimited to, a nanoparticle dispersion. Nanoparticle dispersions caninclude one or more highly dispersed nanoparticle colorants and/orcolorant particles that produce a desired visible color and/or opacityand/or visual effect. Nanoparticle dispersions may include colorantssuch as pigments or dyes having a particle size of less than 150 nm,such as less than 70 nm, or less than 30 nm. Nanoparticles may beproduced by milling stock organic or inorganic pigments with grindingmedia having a particle size of less than 0.5 mm. Example nanoparticledispersions and methods for making them are identified in U.S. Pat. No.6,875,800 B2, which is incorporated herein by reference. Nanoparticledispersions may also be produced by crystallization, precipitation, gasphase condensation, and chemical attrition (i.e., partial dissolution).In order to minimize re-agglomeration of nanoparticles within thecoating, a dispersion of resin-coated nanoparticles may be used. As usedherein, a “dispersion of resin-coated nanoparticles” refers to acontinuous phase in which is dispersed discreet “compositemicroparticles” that comprise a nanoparticle and a resin coating on thenanoparticle. Example dispersions of resin-coated nanoparticles andmethods for making them are identified in U.S. application Ser. No.10/876,031 filed Jun. 24, 2004, which is incorporated herein byreference, and U.S. Provisional Application No. 60/482,167 filed Jun.24, 2003, which is also incorporated herein by reference.

According to the present invention, special effect compositions that maybe used in one or more layers of the multi-layer coating compositeinclude pigments and/or compositions that produce one or more appearanceeffects such as reflectance, pearlescence, metallic sheen,phosphorescence, fluorescence, photochromism, photosensitivity,thermochromism, mechanochromism (strain sensitive pigmentation),goniochromism and/or color-change. Additional special effectcompositions may provide other perceptible properties, such asreflectivity, opacity or texture. For example, special effectcompositions may produce a color shift, such that the color of thecoating changes when the coating is viewed at different angles. Examplecolor effect compositions are identified in U.S. Pat. No. 6,894,086,incorporated herein by reference. Additional color effect compositionsmay include transparent coated mica and/or synthetic mica, coatedsilica, coated alumina, a transparent liquid crystal pigment, a liquidcrystal coating, and/or any composition wherein interference resultsfrom a refractive index differential within the material and not becauseof the refractive index differential between the surface of the materialand the air.

According to the present invention, a photosensitive composition and/orphotochromic composition, which reversibly alters its color when exposedto one or more light sources, can be used in a number of layers in themulti-layer composite. Photochromic and/or photosensitive compositionscan be activated by exposure to radiation of a specified wavelength.When the composition becomes excited, the molecular structure is changedand the altered structure exhibits a new color that is different fromthe original color of the composition. When the exposure to radiation isremoved, the photochromic and/or photosensitive composition can returnto a state of rest, in which the original color of the compositionreturns. For example, the photochromic and/or photosensitive compositionmay be colorless in a non-excited state and exhibit a color in anexcited state. Full color-change may appear within milliseconds toseveral minutes, such as from 20 seconds to 60 seconds. Examplephotochromic and/or photosensitive compositions include photochromicdyes.

The photosensitive composition and/or photochromic composition may beassociated with and/or at least partially bound to, such as by covalentbonding, a polymer and/or polymeric materials of a polymerizablecomponent. In contrast to some coatings in which the photosensitivecomposition may migrate out of the coating and crystallize into thesubstrate, the photosensitive composition and/or photochromiccomposition associated with and/or at least partially bound to a polymerand/or polymerizable component in accordance with the present invention,have minimal migration out of the coating. Example photosensitivecompositions and/or photochromic compositions and methods for makingthem are identified in U.S. application Ser. No. 10/892,919 filed Jul.16, 2004 and incorporated herein by reference.

The primer and/or topcoat layer(s) may optionally further comprisecorrosion inhibitors. The corrosion inhibitors may comprise any of thecorrosion inhibitors discussed above with respect to the aqueousresinous dispersion, and may further comprise magnesium oxide, magnesiumhydroxide, lithium salts, and/or lithium silicates.

According to the present invention, the aqueous resinous dispersionand/or layers deposited from the same, as well as any pretreatmentlayer, primer layer or topcoat layer, may be substantially free,essentially free, or completely free of chromium or chromium-containingcompounds. As used herein, the term “chromium-containing compound”refers to materials that include trivalent chromium or hexavalentchromium. Non-limiting examples of such materials include chromic acid,chromium trioxide, chromic acid anhydride, dichromate salts, such asammonium dichromate, sodium dichromate, potassium dichromate, andcalcium, barium, magnesium, zinc, cadmium, and strontium dichromate.When the aqueous resinous dispersion and/or layers deposited from thesame, as well as any pretreatment layer, primer layer or topcoat layer,is substantially free, essentially free, or completely free of chromium,this includes chromium in any form, such as, but not limited to, thetrivalent chromium-containing compounds and hexavalentchromium-containing compounds listed above.

An aqueous resinous dispersion and/or layers deposited from the same, aswell as any pretreatment layer, primer layer or topcoat layer, that issubstantially free of chromium or chromium-containing compounds meansthat chromium or chromium-containing compounds are not intentionallyadded, but may be present in trace amounts, such as because ofimpurities or unavoidable contamination from the environment. In otherwords, the amount of material is so small that it does not affect theproperties of the composition; this may further include that chromium orchromium-containing compounds are not present in the aqueous resinousdispersion and/or layers deposited from the same, as well as anypretreatment layer, primer layer or topcoat layer, in such a level thatthey cause a burden on the environment. The term “substantially free”means that the aqueous resinous dispersion and/or layers deposited fromthe same, as well as any pretreatment layer, primer layer or topcoatlayer, contain less than 10 ppm of chromium, based on total solidsweight of the composition, the layer, or the layers, respectively, ifany at all. The term “essentially free” means that the aqueous resinousdispersion and/or layers deposited from the same, as well as anypretreatment layer, primer layer or topcoat layer, contain less than 1ppm of chromium, based on total solids weight of the composition or thelayer, or layers, respectively, if any at all. The term “completelyfree” means that the aqueous resinous dispersion and/or layerscomprising the same, as well as any pretreatment layer, primer layer ortopcoat layer, contain less than 1 ppb of chromium, based on totalsolids weight of the composition, the layer, or the layers,respectively, if any at all.

According to the present invention, the coating deposited from theaqueous resinous dispersion describe above may be hydrolytically stable,as determined by the Hydrolytic Stability Test Method. As used herein,the “Hydrolytic Stability Test Method” refers to immersing a baked panelin deionized water at a temperature of 90° C. for 24 hours. The panel isthen removed and baked in an oven set to 150° F. for 60 minutes todehydrate the coating film. The panel is then retested for cureaccording to the Double Acetone Rub Test Method. Whether a coating isconsidered to be hydrolytically stable is demonstrated by the ability ofthe coating to retain acetone resistance after being subjected to thewater soak compared to the acetone resistance of the coating without thewater soak. Specifically, the number of double acetone rubs that thecoating survived following the water soak is compared to the number ofdouble acetone rubs the coating survived without exposure to the watersoak. A coating is considered to be “hydrolytically stable” if thecoating survived a number of double acetone rubs following exposure tothe water soak without reaching the underlying substrate equal to atleast 60% of the double acetone rubs that the coating was able tosurvive without exposure to the water soak, with the caveat that if thecured coating survived 100 or more double acetone rubs without exposureto the water soak, then the cured coating was considered to behydrolytically stable if the coating survived at least 60 double acetonerubs without reaching the substrate. For example, a coating thatsurvived 50 double acetone rubs without exposure to the water soak wasconsidered to be hydrolytically stable if it survived at least 30 doubleacetone rubs following exposure to the water soak. Although reference ismade to the coating prior to exposure to the water soak and afterexposure to the water soak, it should be understood that two differentcoated panels are used with each panel having been coated by the samecomposition by the same technique and cured under the same conditions(i.e., same oven, oven temperature and baking time).

It has been surprisingly discovered that use of the phosphated epoxyresin and aqueous resinous dispersion of the present invention resultsin a cured coating that is hydrolytically stable. Without intending tobe bound by any theory, it is believed that the carbamate functionalgroup of the phosphated epoxy resin forms bonds with curing agents thatare not substantially susceptible to hydrolytic attack.

The present invention is also directed towards a coated substrate,wherein the coated substrate is at least partially coated with theaqueous resinous dispersion described above. The present inventionincludes parts coated with an aqueous resinous dispersion of the presentinvention, and assemblies and apparatus comprising a part coated with anaqueous resinous dispersion of the present invention.

The present invention includes vehicles comprising a part such as asurface coated with the aqueous resinous dispersion of the presentinvention. For example, an aircraft comprising a fuel tank or portion ofa fuel tank coated with the aqueous resinous dispersion of the presentinvention is included within the scope of the invention. The coating maybe in an at least partially cured or fully cured state.

As used herein, the “resin solids” include the phosphated epoxy resin,the curing agent, the carbamate-functional oligomer (if present) and anyadditional water-dispersible non-pigmented component(s) present in thecomposition.

As used herein, the term “alkyl” refers to a substituted orunsubstituted hydrocarbon chain that may be linear or branched and maycomprise one or more hydrocarbon rings that are not aromatic. As usedherein, “aryl” refers to a substituted or unsubstituted hydrocarbonhaving a delocalized conjugated π-system with alternating double andsingle bonds between carbon atoms forming one or more coplanarhydrocarbon rings.

For purposes of the detailed description, it is to be understood thatthe invention may assume various alternative variations and stepsequences, except where expressly specified to the contrary. Moreover,other than in any operating examples, or where otherwise indicated, allnumbers such as those expressing values, amounts, percentages, ranges,subranges and fractions may be read as if prefaced by the word “about,”even if the term does not expressly appear. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are approximations that mayvary depending upon the desired properties to be obtained by the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques. Where a closed or open-ended numerical range is describedherein, all numbers, values, amounts, percentages, subranges andfractions within or encompassed by the numerical range are to beconsidered as being specifically included in and belonging to theoriginal disclosure of this application as if these numbers, values,amounts, percentages, subranges and fractions had been explicitlywritten out in their entirety.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

As used herein, unless indicated otherwise, a plural term can encompassits singular counterpart and vice versa, unless indicated otherwise. Forexample, although reference is made herein to “an” epoxy resin, “a”carbamate functional group, and “a” curing agent, a combination (i.e., aplurality) of these components can be used. In addition, in thisapplication, the use of “or” means “and/or” unless specifically statedotherwise, even though “and/or” may be explicitly used in certaininstances.

As used herein, “including,” “containing” and like terms are understoodin the context of this application to be synonymous with “comprising”and are therefore open-ended and do not exclude the presence ofadditional undescribed or unrecited elements, materials, ingredients ormethod steps. As used herein, “consisting of” is understood in thecontext of this application to exclude the presence of any unspecifiedelement, ingredient or method step. As used herein, “consistingessentially of” is understood in the context of this application toinclude the specified elements, materials, ingredients or method steps“and those that do not materially affect the basic and novelcharacteristic(s)” of what is being described.

As used herein, the terms “on,” “onto,” “applied on,” “applied onto,”“formed on,” “deposited on,” “deposited onto,” mean formed, overlaid,deposited, or provided on but not necessarily in contact with thesurface. For example, an electrodepositable coating composition“deposited onto” a substrate does not preclude the presence of one ormore other intervening coating layers of the same or differentcomposition located between the electrodepositable coating compositionand the substrate.

Whereas specific embodiments of the invention have been described indetail, it will be appreciated by those skilled in the art that variousmodifications and alternatives to those details could be developed inlight of the overall teachings of the disclosure. Accordingly, theparticular arrangements disclosed are meant to be illustrative only andnot limiting as to the scope of the invention which is to be given thefull breadth of the claims appended and any and all equivalents thereof.

ASPECTS

Aspect 1. A phosphated epoxy resin comprising:

at least one terminal group comprising a phosphorous atom covalentlybonded to the resin by a carbon-phosphorous bond or by a phosphoesterlinkage; and

at least one carbamate functional group.

Aspect 2. The phosphated epoxy resin of Aspect 1, wherein the terminalgroup comprises phosphate, organophosphate, phosphonate,organophosphonate, phosphinate, organophosphinate, or combinationsthereof.

Aspect 3. The phosphated epoxy resin of any of the preceding Aspects,wherein the phosphated epoxy resin is substantially free of pendentgroups comprising a phosphorous atom covalently bonded to the resin by acarbon-phosphorous bond or by a phosphoester linkage.

Aspect 4. The phosphated epoxy resin of any of the preceding Aspects,wherein the terminal group of the phosphated epoxy resin comprises thestructure:

wherein R₁ and R₂ each independently represent hydrogen, hydroxyl, analkyl radical, an aryl radical, or a phosphoester group.

Aspect 5. The phosphated epoxy resin of any of the preceding Aspects,wherein the phosphated epoxy resin comprises at least one pendent groupcomprising the carbamate functional group, the pendent group comprisingthe structure:

wherein R represents remainder of phosphated epoxy resin.

Aspect 6. The phosphated epoxy resin of any of the preceding Aspects,wherein the phosphated epoxy resin comprises the following structure:

wherein R₁, R₂, R₃ and R₄ each independently represent hydrogen,hydroxyl, an alkyl radical, an aryl radical, or a phosphoester group,and R represents the residue of an epoxy functional polymer comprisingat least one carbamate functional group.

Aspect 7. The phosphated epoxy resin of any of the preceding Aspects,wherein the phosphated epoxy resin comprises at least one constitutionalunit A comprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical.

Aspect 8. The phosphated epoxy resin of Aspect 7, wherein the phosphatedepoxy resin further comprises at least one constitutional unit Bcomprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical.

Aspect 9. The phosphated epoxy resin of Aspect 8, wherein the ratio ofconstitutional unit A to constitutional unit B is from 1:20 to 20:1.

Aspect 10. The epoxy resin of any of Aspects 1-7, wherein the phosphatedepoxy resin comprises the structure:

wherein m is 1 to 2,000 and n is 0 to 2,000; d R₂ each independentlyrepresent hydrogen, an alkyl radical or an aryl radical; R₃ and R₄ eachindependently represent hydrogen, hydroxyl, an alkyl radical, an arylradical, or a phosphoester group.

Aspect 11. An aqueous resinous dispersion comprising:

(a) the phosphated epoxy resin according to any of Aspects 1-10; and

(b) a curing agent.

Aspect 12. The aqueous resinous dispersion of Aspect 11, wherein thecuring agent comprises at least two functional groups reactive withcarbamate functional groups.

Aspect 13. The aqueous resinous dispersion of any of Aspects 11 or 12,wherein the curing agent comprises an aminoplast resin, a phenoplastresin, a blocked polyisocyanate, or combinations thereof.

Aspect 14. The aqueous resinous dispersion of any of Aspects 11-13,wherein the resinous dispersion is substantially free ofmetal-containing catalysts.

Aspect 15. The aqueous resinous dispersion of any of Aspects 11-14,further comprising a carbamate-functional oligomer comprising at leasttwo carbamate groups.

Aspect 16. The aqueous resinous dispersion of Aspect 15, wherein thecarbamate-functional oligomer comprises the structure:

Aspect 17. A method of making the phosphated epoxy resin of any ofAspects 1-10, the method comprising:

reacting an epoxy resin comprising at least one terminal epoxidefunctional group and at least one pendant hydroxyl functional group witha molecule comprising an isocyanato functional group and a carbamatefunctional group, wherein the pendant hydroxyl functional group andisocyanato functional group react to form a urethane linkage, wherebythe molecule is incorporated into the epoxy resin to form acarbamate-functional epoxy resin; and

further reacting the carbamate-functional epoxy resin with a phosphoricacid, a phosphonic acid, a phosphinic acid, or combinations thereof,wherein the at least one terminal epoxide functional group of thecarbamate-functional epoxy resin reacts with an acid group of thephosphoric acid or phosphonic acid, whereby the phosphoric acid, thephosphonic acid, and/or the phosphinic acid is incorporated into thecarbamate-functional epoxy resin to form a phosphated,carbamate-functional epoxy resin.

Aspect 18. The method of Aspect 17, wherein the phosphated,carbamate-functional epoxy resin is neutralized with a base.

Aspect 19. A method of coating a substrate, comprisingelectrophoretically depositing the aqueous resinous dispersion of any ofAspects 11-16 onto the substrate to form a coating on the substrate.

Aspect 20. A coated substrate, wherein the coated substrate is at leastpartially coated with the resinous dispersion of any of Aspects 11-16.

Aspect 21. An aqueous resinous dispersion comprising:

(a) an epoxy resin; and

(b) a carbamate-functional oligomer comprising at least two carbamategroups.

Aspect 22. The aqueous resinous dispersion of Aspect 21, wherein thecarbamate-functional oligomer comprises the structure:

Aspect 23. The aqueous resinous dispersion of Aspect 21 or 22, furthercomprising a curing agent.

Illustrating the invention are the following examples, which, however,are not to be considered as limiting the invention to their details.Unless otherwise indicated, all parts and percentages in the followingexamples, as well as throughout the specification, are by weight.

EXAMPLES Example 1—Preparation of an Aqueous Resinous Dispersion of aHydroxyl-Functional Phosphated Epoxy Resin Example 1A

A general procedure for making an aqueous resinous dispersion of ahydroxyl-functional phosphated epoxy resin was performed as follows:

Charge # Material Amount (g) 1 Bisphenol-A Diglycidyl Ether 141.4 2Bisphenol-A 45.5 3 Butyl CELLOSOLVE¹ 14.1 4 2-Ethyl-1-hexanol 21.2 5Ethyltriphenylphosphonium Bromide 0.1 6 Ektasolve EEH² 20.5 7 85%Phosphoric Acid 5.5 8 Phenylphosphonic Acid 3.3 9 Ektasolve EEH 0.9 10Deionized water 9.6 11 Diisopropanolamine 15.6 12 Cymel 1130³ 70.2 13Deionized water 138.1 14 Deionized water 247.8 ¹2-Butoxyethanolavailable from Dow Chemical Company ²Ethylene glycol 2-ethylhexyl etheravailable from Eastman Chemical Company ³Cymel 1130 amethylated/n-butylated melamine-formaldehyde crosslinker available fromAllnex (98% ± 2% non-volatile content)

Charges 1-5 were added to a flask set up for total reflux with stirringunder nitrogen and heated to 130° C. and allowed to exotherm to 160° C.The mixture was held at 160° C. for 1 hour. After 1 hour, charge 6 wasadded while cooling to 90° C. When 90° C. was reached, charges 7-9 wereadded and the mixture was allowed to exotherm. The temperature wasadjusted to 120° C. and the mixture was held at that temperature for 30minutes, then cooled to 100° C. Charge 10 was added slowly and themixture was held at 100° C. for 1 hour, then cooled to 90° C. Charge 11was added followed by charge 12. The mixture was stirred for 30 minutesas the temperature was readjusted to 90° C. The resulting mixture wasthen reverse thinned into charge 13, which was at ambient temperature,and held for 30 minutes. Charge 14 was then added and held for 30minutes. The total solids of the aqueous resinous dispersion was 35.1%solids. Final molecular weight of the phosphated epoxy resin asdetermined by GPC (Mz) was 253,961.

Example 1B

The hydroxyl-functional phosphated epoxy resin of Example 1A wasformulated into a paint using the following procedure:

Charge # Material Amount (g) 1 Aqueous resinous dispersion of Example 1A1200.7 2 ACPP2220¹ 239.0 3 Deionized water 1360.3 ¹Commerciallyavailable pigment paste available from PPG Industries, Inc.

Charge 1 was added to a 1-gallon plastic bucket and agitation wasstarted. Charge 2 was added slowly over 5 minutes. Finally, charge 3 wasadded over 5 minutes and the resulting mixture stirred for an additional15 minutes.

After ultrafiltration, the paint was electrodeposited (130V/90s/75° F./)onto 2024 T3 aluminum panel with the aluminum panel serving as the anodeand baked in an oven set to a temperature of 250° F. for 30 minutes. Thepanels were prepared as follows prior to electrocoating for each exampleincluded herein: The 2024 T3 aluminum alloy panels were wiped cleanusing an acetone-soaked wipe and were then immersed in RIDOLENE 298 (analkaline cleaner commercially available from Henkel Corp.) for 2 minutesat 130° F. (54.4° C.) followed by a 1-minute immersion in tap water. Thepanels were then immersed in TURCO 6/16 deoxidizer bath (commerciallyavailable from Henkel Corp. and prepared according to manufacturerinstructions) at ambient conditions for 2.5 minutes, followed by a1-minute immersion in tap water. The panels were then spray rinsed withdeionized water and allowed to dry under ambient conditions for 1-2hours prior to electrocoating application.

The baked substrate was tested for cure according to the Double AcetoneRub Test Method. The coating of Example 1B passed the Double Acetone RubTest Method by surviving 100 double acetone rubs (DAR) without reachingthe underlying substrate.

The baked panel was also tested for the presence of filiform corrosionaccording to the Filiform Corrosion Test Method. Filiform corrosion waspresent in the form of filaments measuring 1 mm.

The baked panel was also evaluated for hydrolytic stability according tothe Hydrolytic Stability Test Method. The film was determined to lackhydrolytic stability as measured according to the Hydrolytic StabilityTest Method because the rubbing wore through the coating to expose theunderlying substrate after only 4 double acetone rubs.

Example 2—Preparation of a Carbamate-Functional Oligomer

A reaction schematic and general procedure for making acarbamate-functional oligomer (hydroxypropylcarbamate fully-cappedhexamethylene diisocyanate trimer) was performed as follows:

Chare # Material Amount (g) 1 Hexamethylene Diisocyanate Trimer¹ 970.0 2Methyl isobutyl ketone 362.4 3 Dibutyltindilaurate 1.6 4 Carbalink HPC(95% solids)² 639.4 ¹Available as Desmodur N 3300 from Covestro²Hydroxypropylcarbamate commercially available from Huntsman

Charges 1-3 were added to a flask set up for total reflux with stirringunder nitrogen. The mixture was heated to a temperature of 60° C. Charge4 was added over 2 hours through an addition funnel while the resultingexotherm was maintained under 60° C. After 2 hours, the mixture revealedno residual isocyanate peak by IR (2200-2300 cm⁻¹). The mixture was thencooled to 40° C. and poured out. Final solids were 84.2%. Finalmolecular weight as determined by GPC (Mz) was 2,999.

Example 3—Preparation of an Aqueous Resinous Dispersion of aHydroxyl-Functional Phosphated Epoxy Resin and Carbamate-FunctionalOligomer Example 3A

A general procedure for making an aqueous resinous dispersion of ahydroxyl-functional phosphated epoxy resin and the carbamate-functionaloligomer of Example 2 was performed as follows:

Charge # Material Amount (g) 1 Bisphenol-A Diglycidyl Ether 184.4 2Bisphenol-A 59.4 3 Butyl carbitol formal 7.5 4 EthyltriphenylphosphoniumBromide 0.2 5 Methyl isobutyl ketone 19.5 6 Ektasolve EEH 41.4 7 ButylCELLOSOLVE 37.3 8 2-Ethyl-1-hexanol 49.7 9 85% Phosphoric Acid 14.6 10Phenylphosphonic Acid 12.7 11 Ektasolve EEH 4.1 12 Deionized water 31.013 Diisopropanolamine 49.6 14 Cymel 1130 106.2 15 Carbamate functionaloligomer of Example 2 336.3 16 Deionized water 358.6 17 Deionized water532.4

Charges 1-4 were added to a flask set up for total reflux with stirringunder nitrogen and heated to 130° C. and allowed to exotherm to 160° C.The mixture was held at 160° C. for 1 hour. After 1 hour, charge 5 wasadded while cooling to 90° C. When 90° C. was reached, charges 6-8 wereadded followed by charges 9-11. The mixture was allowed to exotherm andthe temperature was adjusted to 120° C. The mixture was held at thattemperature for 30 minutes, then cooled to 100° C. Charge 12 was addedslowly and the mixture was held at 100° C. for 1 hour, then cooled to90° C. Charge 13 was added followed by charge 14, and then charge 15.The mixture was stirred for 30 minutes as the temperature was readjustedto 90° C. The resulting mixture was then reverse thinned into charge 16,which was at ambient temperature, and held for 30 minutes. Charge 17 wasthen added and held for 30 minutes. Final solids were 33.5%. Finalmolecular weight of the phosphated epoxy resin as determined by GPC (Mz)was 354,257.

Example 3B

The aqueous resinous dispersion of Example 3A was formulated into apaint using the following procedure:

Charge # Material Amount (g) 1 Aqueous resinous dispersion of Example 3A1313.8 2 ACPP2220 239.0 3 Deionized water 1247.2

Charge 1 was added to a 1-gallon plastic bucket and agitation wasstarted. Charge 2 was added slowly over 5 minutes. Finally, charge 3 wasadded over 5 minutes and the resulting mixture stirred for an additional15 minutes.

After ultrafiltration, the paint was electrodeposited (95V/90s/75° F./)onto 2024 T3 aluminum panel with the aluminum panel serving as the anodeand baked in an oven set to a temperature of 250° F. for 30 minutes.

The baked substrate was tested for cure according to the Double AcetoneRub Test Method. The coating of Example 3B passed the Double Acetone RubTest Method by surviving 100 double acetone rubs (DAR) without reachingthe underlying substrate.

The baked panel was also tested for the presence of filiform corrosionaccording to the Filiform Corrosion Test Method. Filiform corrosion wasnot detected because no filaments were found along the scribed area.

Example 4—Preparation of a Molecule Carbamate-Functional Molecule

A reaction schematic and general procedure for making acarbamate-functional molecule, hydroxypropylcarbamate half-cappedisophoronediisocyanate, was performed as follows:

Charge # Material Amount (g) 1 Isophoronediisocyanate 889.6 2 Methylisobutyl ketone 430.3 3 Dibutyltindilaurate 1.4 4 Carbalink HPC (95%solids) 501.5

Charges 1-3 were added to a flask set up for total reflux with stirringunder nitrogen. The mixture was heated to a temperature of 60° C. Charge4 was added over 2 hours through an addition funnel while the resultingexotherm was maintained under 70° C. After 2 hours, the mixture wastitrated for isocyanate (NCO) equivalent weight and found to have avalue of 490 g/eq of NCO (theoretical value determined to be 456 g/eq).The mixture was then cooled to 40° C. and poured out. Final solids were75.8%. Final molecular weight as determined by GPC (Mz) was 585.

Example 5—Preparation of an Aqueous Resinous Dispersion of aCarbamate-Functional Phosphated Epoxy Resin Example 5A

A general procedure for making a carbamate-functional phosphated epoxyresin was performed as follows:

Charge # Material Amount (g) 1 Bisphenol-A Diglycidyl Ether 258.2 2Bisphenol-A 83.1 3 Butyl carbitol formal 10.6 4Ethyltriphenylphosphonium Bromide 0.2 5 Methyl isobutyl ketone 49.7 6Dibutyltindilaurate 0.5 7 Carbamate-functional molecule of Example 4157.8 8 Ektasolve EEH 112.7 9 Butyl CELLOSOLVE 87.9 10 2-Ethyl-1-hexanol72.1 11 85% Phosphoric Acid 14.5 12 Phenylphosphonic Acid 15.8 13Ektasolve EEH 27.3 14 Deionized water 33.8 15 Diisopropanolamine 54.0 16Cymel 1130 181.0 17 Deionized water 205.5 18 Deionized water 544.6

Charges 1-4 were added to a flask set up for total reflux with stirringunder nitrogen and heated to 130° C. and allowed to exotherm to 160° C.The mixture was held at 160° C. for 1 hour. After 1 hour, charge 5 wasadded while cooling to 80° C. When 80° C. was reached, charge 6 wasadded followed by charge 7 over 1 hour. After 1 hour, residual NCO waschecked by IR and none remained. The mixture was then warmed to 90° C.When 90° C. was reached, charges 8-10 were added followed by charges11-13. The mixture was allowed to exotherm and the temperature wasadjusted to 120° C. The mixture was held at that temperature for 30minutes, then cooled to 100° C. Charge 14 was added slowly and themixture was held at 100° C. for 1 hour, then cooled to 90° C. Charge 15was added followed by charge 16. The mixture was stirred for 30 minutesas the temperature was readjusted to 90° C. The resulting mixture wasthen reverse thinned into charge 17, which was at ambient temperature,and held for 30 minutes. Charge 18 was then added and held for 30minutes. Final solids were 36.1%. Final molecular weight as determinedby GPC (Mz) was 92,585.

The phosphated epoxy resin was also tested to determine whether thecarbamate-functional molecule of Example 4 was present on the phosphatedepoxy resin. Electrospray ionization mass spectrometry (ESI-MS) analysisdetermined that by comparison to starting epoxy polymer, the massdifference of hydroxypropylcarbamate half-capped isophoronediisocyanate(341 Da) was found in the reaction product of the two, indicating thatthe hydroxypropylcarbamate half-capped isophoronediisocyanate wasreacted onto the epoxy polymer backbone.

Example 5B

The aqueous resinous dispersion of Example 5A was formulated into apaint using the following procedure:

Charge # Material Amount (g) 1 Aqueous Resinous Dispersion of Example 5A1216.7 2 ACPP2220 239.1 3 Deionized water 1345.0

Charge 1 was added to a 1-gallon plastic bucket and agitation wasstarted. Charge 2 was added slowly over 5 minutes. Finally, charge 3 wasadded over 5 minutes and the resulting mixture stirred for an additional15 minutes.

After ultrafiltration, the paint was electrodeposited (85V/90s/75° F./)onto 2024 T3 aluminum panel with the aluminum panel serving as the anodeand baked in an oven set to a temperature of 250° F. for 60 minutes.

The baked substrate was tested for cure according to the Double AcetoneRub Test Method. The coating of Example 5B passed the Double Acetone RubTest Method by surviving 100 double acetone rubs (DAR) without reachingthe underlying substrate.

The baked panel was also tested for the presence of filiform corrosionaccording to the Filiform Corrosion Test Method. Filiform corrosion waspresent in the form of filaments measuring 1 mm.

The baked panel was also evaluated for hydrolytic stability according tothe Hydrolytic Stability Test Method. The film was determined to possesshydrolytic stability as measured according to the Hydrolytic StabilityTest Method because the coating survived 100 double acetone rubs withoutexposing the underlying substrate.

Example 6—Preparation of Aqueous Resinous Dispersion of a PhosphatedEpoxy Resin Example 6A

A general procedure for making a phosphated epoxy resin by phosphatingbefore incorporating carbamate groups was performed as follows:

Charge # Material Amount (g) 1 Bisphenol-A Diglycidyl Ether 245.9 2Bisphenol-A 79.2 3 Butyl carbitol formal 10.1 4Ethyltriphenylphosphonium Bromide 0.2 5 Methyl isobutyl ketone 47.3 6Ektasolve EEH 107.3 7 Butyl CELLOSOLVE 83.7 8 2-Ethyl-1-hexanol 68.7 985% Phosphoric Acid 13.8 10 Phenylphosphonic Acid 15.0 11 Ektasolve EEH26.0 12 Deionized water 32.2 13 Dibutyltindilaurate 0.5 14Carbamate-functional molecule of Example 4 143.9 15 Diisopropanolamine51.5 16 Cymel 1130 169.4 17 Deionized water 183.6 18 Deionized water509.6

Charges 1-4 were added to a flask set up for total reflux with stirringunder nitrogen and heated to 130° C. and allowed to exotherm to 160° C.The mixture was held at 160° C. for 1 hour. After 1 hour, charges 5-8were added while cooling to 90° C. When 90° C. was reached, charges 9-11were added. The mixture was allowed to exotherm and the temperature wasadjusted to 120° C. The mixture was held at that temperature for 30minutes, then cooled to 100° C. When 100° C. was reached, charge 12 wasadded slowly and the mixture was held at 100° C. for 1 hour, then cooledto 80° C. Charge 13 was added followed by charge 14 over 1 hour. After 1hour, residual NCO was checked by IR and none remained. The mixture wasthen warmed to 90° C. Charge 15 was added followed by charge 16. Themixture was stirred for 30 minutes as the temperature was readjusted to90° C. The resulting mixture was then reverse thinned into charge 17,which was at ambient temperature, and held for 30 minutes. Charge 18 wasthen added and held for 30 minutes. Final solids were 38.0%. Finalmolecular weight as determined by GPC (Mz) was 247,561.

The phosphated epoxy resin was also tested by electrospray ionizationmass spectrometry to determine whether the carbamate-functional moleculeof Example 4 was present on the phosphated epoxy resin. The massdifference of the carbamate-functional molecule of Example 4 (341 Da)was not found in the phosphated epoxy resin after attempted reactionwith the carbamate-functional molecule of Example 4. These resultsindicated that the carbamate-functional molecule of Example 4 was likelynot reacted onto the phosphated epoxy resin, and, accordingly, that thephosphated epoxy polymer did not include carbamate functional groups.

Example 6B

The aqueous resinous dispersion of Example 6A was formulated into apaint using the following procedure:

Charge # Material Amount (g) 1 Aqueous Resinous Dispersion of Example 6A1158.0 2 ACPP2220 239.0 3 Deionized water 1403.0

Charge 1 was added to a 1-gallon plastic bucket and agitation wasstarted. Charge 2 was added slowly over 5 minutes. Finally, charge 3 wasadded over 5 minutes and the resulting mixture stirred for an additional15 minutes.

After ultrafiltration, the paint was electrodeposited (60V/60s/75° F.)onto 2024 T3 aluminum panel with the aluminum panel serving as the anodeand baked in an oven set to a temperature of 250° F. for 60 minutes.

The baked substrate was tested for cure according to the Double AcetoneRub Test Method. The coating of Example 6B passed the Double Acetone RubTest Method by surviving 100 double acetone rubs (DAR) without reachingthe underlying substrate.

The baked panel was also evaluated for hydrolytic stability according tothe Hydrolytic Stability Test Method. The film was determined to lackhydrolytic stability as measured according to the Hydrolytic StabilityTest Method because the rubbing wore through the coating to expose theunderlying substrate after 53 double acetone rubs.

Example 7—Preparation of an Aqueous Resinous Dispersion of aCarbamate-Functional Phosphated Epoxy Resin and Carbamate-FunctionalOligomer Example 7A

A general procedure for making an aqueous resinous dispersion of acarbamate-functional phosphated epoxy resin and the carbamate-functionaloligomer of Example 2 was performed as follows:

Charge # Material Amount (g) 1 Bisphenol-A Diglycidyl Ether 196.7 2Bisphenol-A 63.3 3 Butyl carbitol formal 8.0 4 EthyltriphenylphosphoniumBromide 0.2 5 Methyl isobutyl ketone 37.8 6 Dibutyltindilaurate 0.4 7Carbamate-functional molecule of Example 4 120.2 8 Ektasolve EEH 85.9 9Butyl CELLOSOLVE 67.0 10 2-Ethyl-1-hexanol 55.0 11 85% Phosphoric Acid11.0 12 Phenylphosphonic Acid 12.0 13 Ektasolve EEH 20.8 14 Deionizedwater 25.8 15 Diisopropanolamine 41.2 16 Cymel 1130 188.0 17Carbamate-functional oligomer of Example 2 178.7 18 Deionized water294.6 19 Deionized water 565.8

Charges 1-4 were added to a flask set up for total reflux with stirringunder nitrogen and heated to 130° C. and allowed to exotherm to 160° C.The mixture was held at 160° C. for 1 hour. After 1 hour, charge 5 wasadded while cooling to 80° C. When 80° C. was reached, charge 6 wasadded followed by charge 7 over 1 hour. After 1 hour, residual NCO waschecked by IR and none remained. The mixture was then warmed to 90° C.When 90° C. was reached, charges 8-10 were added followed by charges11-13. The mixture was allowed to exotherm and the temperature wasadjusted to 120° C. The mixture was held at that temperature for 30minutes, then cooled to 100° C. Charge 14 was added slowly and themixture was held at 100° C. for 1 hour, then cooled to 90° C. Charge 15was added followed by charge 16, then charge 17. The mixture was stirredfor 30 minutes as the temperature was readjusted to 90° C. The resultingmixture was then reverse thinned into charge 18, which was at ambienttemperature, and held for 30 minutes. Charge 19 was then added and heldfor 30 minutes. Final solids were 34.5%. Final molecular weight asdetermined by GPC (Mz) was 89,973.

The carbamate-functional epoxy polymer containing phosphoric andphosphonic acid with a low molecular weight carbamate was formulatedinto a paint using the following procedure:

Charge # Material Amount (g) 1 Aqueous resinous dispersion of Example 7A1273.0 2 ACPP2220 239.1 3 Deionized water 1288.6

Charge 1 was added to a 1-gallon plastic bucket and agitation wasstarted. Charge 2 was added slowly over 5 minutes. Finally, charge 3 wasadded over 5 minutes and the resulting mixture stirred for an additional15 minutes.

After ultrafiltration, the paint was electrodeposited (80V/90s/75° F.)onto 2024 T3 aluminum panel with the aluminum panel serving as the anodeand baked in an oven set to a temperature of 250° F. for 60 minutes.

The baked substrate was tested for cure according to the Double AcetoneRub Test Method. The coating of Example 7B passed the Double Acetone RubTest Method by surviving 100 double acetone rubs (DAR) without reachingthe underlying substrate.

The baked panel was also tested for the presence of filiform corrosionaccording to the Filiform Corrosion Test Method. Filiform corrosion wasnot detected because no filaments were found along the scribed area.

TABLE 1 Summary of Cure and Hydrolytic Stability Performance HydrolyticEx # Polymer Functionality Cure Stability 1B Hydroxyl Pass Fail 5BCarbamate (carbamate groups added before Pass Pass phosphating) 6BHydroxyl (attempt to add carbamate groups Pass Fail after phosphatingwas not successful)¹ ¹As discussed above, although a reaction wasattempted to add carbamate functional groups onto the resin backboneafter the resin was phosphated, carbamate functional groups were notdetected on the resin when tested by electrospray ionization massspectrometry. Since the reaction was not successful, the hydroxylfunctional groups were not substituted by carbamate functional groups,and the polymer functionality would have been hydroxyl.

As shown in Table 1, both the hydroxyl functional phosphated epoxy resinand the carbamate functional phosphated epoxy resin achieve passing cureperformance when baked at 250° F. for 60 minutes with an alkoxylatedmelamine curing agent. However, the film resulting from the hydroxylfunctional phosphated epoxy resin did not retain its film integrityafter hydrolytic stability testing. Without intending to be bound by anytheory, it is believed that the instability of the cured film is due tothe hydrolytically unstable nature of the hydroxyl-melamine bond.

In contrast, the film resulting from the carbamate-functional phosphatedepoxy resin retained its film integrity after hydrolytic stabilitytesting. The stability of the film indicates that the carbamate-melaminebond is hydrolytically stable and resistant to hydrolytic attack. Thestability of the film resulting from the carbamate-functional phosphatedepoxy resin was a surprising result.

TABLE 2 Filiform Corrosion Performance Summary Size of Polymer FilamentsEx # Functionality Carbamate-functional oligomer (mm) 1B Hydroxyl — 1 3BHydroxyl Hydroxypropylcarbamate fully-capped 0 hexamethylenediisocyanate trimer 5B Carbamate — 1 7B Carbamate Hydroxypropylcarbamatefully-capped 0 hexamethylene diisocyanate trimer

Addition of a hydroxypropylcarbamate fully-capped hexamethylenediisocyanate trimer to either a hydroxyl and/or carbamate-functionalpolymer system made an improvement to filiform corrosion resistance asindicated by the presence of no measurable filaments compared tocorresponding systems that do not contain the carbamate-functionaloligomer as indicated by the presence of filaments.

It will be appreciated by skilled artisans that numerous modificationsand variations are possible in light of the above disclosure withoutdeparting from the broad inventive concepts described and exemplifiedherein. Accordingly, it is therefore to be understood that the foregoingdisclosure is merely illustrative of various exemplary aspects of thisapplication and that numerous modifications and variations can bereadily made by skilled artisans which are within the spirit and scopeof this application and the accompanying claims.

We claim:
 1. A phosphated epoxy resin comprising: at least one terminalgroup comprising a phosphorous atom covalently bonded to the resin by acarbon-phosphorous bond or by a phosphoester linkage; and at least onecarbamate functional group; wherein the terminal group of the phosphatedepoxy resin comprises the structure:

wherein R₁ and R₂ each independently represent hydrogen, hydroxyl, analkyl radical, an aryl radical, or a phosphoester group, and wherein thephosphated epoxy resin comprises at least one constitutional unit Acomprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical.
 2. The phosphated epoxy resin of claim 1,wherein the phosphated epoxy resin further comprises at least oneconstitutional unit B comprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical.
 3. The phosphated epoxy resin of claim 2,wherein the ratio of constitutional unit A to constitutional unit B isfrom 1:20 to 20:1.
 4. A method of making the phosphated epoxy resin ofclaim 1, the method comprising: reacting an epoxy resin comprising atleast one terminal epoxide functional group and at least one pendanthydroxyl functional group with a molecule comprising an isocyanatofunctional group and a carbamate functional group, wherein the pendanthydroxyl functional group and isocyanato functional group react to forma urethane linkage, whereby the molecule is incorporated into the epoxyresin to form a carbamate-functional epoxy resin; and further reactingthe carbamate-functional epoxy resin with a phosphoric acid, aphosphonic acid, a phosphinic acid, or combinations thereof, wherein theat least one terminal epoxide functional group of thecarbamate-functional epoxy resin reacts with an acid group of thephosphoric acid or phosphonic acid, whereby the phosphoric acid and/orthe phosphonic acid is incorporated into the carbamate-functional epoxyresin to form the phosphated epoxy resin comprising at least onecarbamate functional group.
 5. The method of claim 4, wherein thephosphated epoxy resin comprising at least one carbamate functionalgroup is neutralized with a base.
 6. An aqueous resinous dispersioncomprising: (a) the phosphated epoxy resin of claim 1; and (b) acarbamate-functional oligomer comprising at least two carbamatefunctional groups.
 7. An aqueous resinous dispersion comprising: (a) aphosphated epoxy resin comprising: (i) at least one terminal groupcomprising a phosphorous atom covalently bonded to the resin by acarbon-phosphorous bond or by a phosphoester linkage; and (ii) at leastone carbamate functional group; and (b) a curing agent; wherein theterminal group of the phosphated epoxy resin comprises the structure:

wherein R₁ and R₂ each independently represent hydrogen, hydroxyl, analkyl radical, an aryl radical, or a phosphoester group, and wherein thephosphated epoxy resin comprises at least one constitutional unit Acomprising the structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical.
 8. The aqueous resinous dispersion of claim7, wherein the terminal group comprises phosphate, organophosphate,phosphonate, organophosphonate, phosphinate, organophosphinate, orcombinations thereof.
 9. The aqueous resinous dispersion of claim 7,wherein the phosphated epoxy resin comprises the structure:

wherein R₁, R₂, R₃ and R₄ each independently represent hydrogen,hydroxyl, an alkyl radical, an aryl radical, or a phosphoester group,and R represents the residue of an epoxy functional polymer comprisingat least one carbamate functional group.
 10. The aqueous resinousdispersion of claim 7, wherein the phosphated epoxy resin issubstantially free of pendent groups comprising a phosphorous atomcovalently bonded to the resin by a carbon-phosphorous bond or by aphosphoester linkage.
 11. The aqueous resinous dispersion of claim 7,wherein the phosphated epoxy resin comprises at least one pendent groupcomprising the carbamate functional group, the pendent group comprisingthe structure:

wherein R represents remainder of the phosphated epoxy resin.
 12. Theaqueous resinous dispersion of claim 7, wherein the phosphated epoxyresin further comprises at least one constitutional unit B comprisingthe structure:

wherein R₁ and R₂ each independently represent hydrogen, an alkylradical or an aryl radical.
 13. The aqueous resinous dispersion of claim12, wherein the ratio of constitutional unit A to constitutional unit Bis from 1:20 to 20:1.
 14. The aqueous resinous dispersion of claim 7,wherein the phosphated epoxy resin comprises the structure:

wherein m is 1 to 2,000 and n is 0 to 2,000; R₁ and R₂ eachindependently represent hydrogen, an alkyl radical or an aryl radical;R₃ and R₄ each independently represent hydrogen, hydroxyl, an alkylradical, an aryl radical, or a phosphoester group.
 15. The aqueousresinous dispersion of claim 7, wherein the curing agent comprises atleast two functional groups reactive with carbamate functional groups.16. The aqueous resinous dispersion of claim 7, wherein the curing agentcomprises an aminoplast resin, a phenoplast resin, a blockedpolyisocyanate, or combinations thereof.
 17. The aqueous resinousdispersion of claim 7, wherein the aqueous resinous dispersion issubstantially free of metal-containing catalysts.
 18. The aqueousresinous dispersion of claim 7, further comprising acarbamate-functional oligomer comprising at least two carbamatefunctional groups.
 19. The aqueous resinous dispersion of claim 18,wherein the carbamate-functional oligomer comprises the structure:


20. A method of coating a substrate comprising electrophoreticallydepositing the aqueous resinous dispersion of claim 7 onto the substrateto form a coating on the substrate.
 21. The method of claim 20, whereinthe coating deposited from the aqueous resinous dispersion of claim 7cures at a bake temperature of 250° F. in 60 minutes or less, asmeasured by surviving at least 25 double acetone rubs according toDouble Acetone Rub Test Method.
 22. The method of claim 20, wherein thecoating deposited from the aqueous resinous dispersion of claim 7 ishydrolytically stable, as determined by the Hydrolytic Stability TestMethod.
 23. The method of claim 20, wherein the aqueous resinousdispersion further comprises a carbamate-functional oligomer, and thecoating deposited from the aqueous resinous dispersion demonstrates adecreased length of filiform corrosion when compared to a comparativecoating composition that does not include the carbamate-functionaloligomer, as measured according to the Filiform Corrosion Test Method.24. A coated substrate, wherein the coated substrate is at leastpartially coated with the aqueous resinous dispersion of claim
 7. 25. Apart at least partially coated with the aqueous resinous dispersion ofclaim
 7. 26. A vehicle comprising the part of claim
 25. 27. The vehicleof claim 26, wherein the vehicle comprises an aerospace vehicle.
 28. Avehicle at least partially coated with the aqueous resinous dispersionof claim
 7. 29. The vehicle of claim 28, wherein the vehicle comprisesan aerospace vehicle.